[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"cheat-sheet---en":3,"domain-info---en":3,"topic-info----en":3,"lesson-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-deployment-models-public-and-private-clouds-en":4,"next-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-deployment-models-public-and-private-clouds-en":232,"prev-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-deployment-models-public-and-private-clouds-en":438},null,{"locked":5,"reason":3,"meta":6,"item":17},false,{"title":7,"description":8,"isFree":9,"estimatedMinutes":10,"difficulty":11,"learningObjectives":12},"Public and Private Clouds","Who owns the hardware and who else can share it: the NIST definitions of public, private, and community cloud, and how to choose between them based on cost, control, and compliance.",true,16,"beginner",[13,14,15,16],"Define the public, private, and community cloud deployment models using the NIST framework","Compare the cost, control, and security tradeoffs between public and private cloud","Identify which deployment model fits a scenario based on who owns the hardware and who else shares it","Explain why a virtualized on-premises environment does not automatically qualify as a private cloud",{"id":18,"title":7,"body":19,"description":8,"difficulty":11,"estimatedMinutes":10,"extension":181,"infographics":182,"isFree":9,"learningObjectives":183,"meta":184,"navigation":9,"path":185,"quiz":186,"seo":229,"stem":230,"__hash__":231},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/01-public-and-private-clouds.md",{"type":20,"value":21,"toc":169},"minimark",[22,27,31,34,38,41,44,48,51,54,57,61,64,67,71,152,156,159,162,166],[23,24,26],"h2",{"id":25},"who-owns-the-hardware-youre-using","Who owns the hardware you're using",[28,29,30],"p",{},"A hospital network wants to run its patient portal on infrastructure it can scale up during flu season and scale back down in summer. Its compliance officer also insists that patient records never leave hardware the hospital itself controls: no shared servers, no unknown neighbor's workload running next to it. Three blocks away, a 3-person startup wants the opposite: no data center, no IT staff, and a product ready to launch in 6 weeks.",[28,32,33],{},"Both teams want cloud characteristics, on-demand self-service, elastic scale, but they cannot get them from the same infrastructure. That difference, who owns the hardware and who else is allowed to share it, is what a cloud deployment model describes. This lesson covers the 3 models NIST defines around exclusivity: public, private, and community cloud. The next lesson covers what happens when you combine them.",[23,35,37],{"id":36},"public-cloud-one-provider-many-tenants","Public cloud: one provider, many tenants",[28,39,40],{},"In a public cloud, an external provider such as AWS, Microsoft Azure, or Google Cloud owns and operates the hardware, then sells access to it as a service to anyone willing to pay. NIST's definition is blunt about the audience: the infrastructure is \"provisioned for open use by the general public.\" You do not own a single server. You rent capacity, a virtual machine, a storage bucket, a managed database, from a shared pool that thousands of other customers also draw from, and the provider's software keeps every customer's data and workload isolated from the others.",[28,42,43],{},"That shared pool is exactly what makes public cloud economical. Because the provider spreads the cost of its data centers across every customer, you get the scale, service variety, and pay-as-you-go pricing that made the 3-person startup's 6-week launch possible in the first place. AWS puts the tradeoff plainly in its own guidance: for nearly every use case, public cloud wins on cost, breadth of services, and how fast you can start, precisely because you are not paying to build or run any of the infrastructure yourself.",[23,45,47],{"id":46},"private-cloud-one-organization-dedicated-hardware","Private cloud: one organization, dedicated hardware",[28,49,50],{},"A private cloud flips the ownership. NIST defines it as infrastructure \"provisioned for exclusive use by a single organization.\" That organization, not a public provider, controls who touches the hardware, where it physically sits, and how it is secured, which is exactly what the hospital's compliance officer was asking for.",[28,52,53],{},"Here is the boundary that trips people up: owning virtualized on-premises servers does not automatically make them a private cloud. A real cloud still has to clear all 5 NIST characteristics from the previous topic, and on-demand self-service is one of them. A data center where developers file a ticket and wait 2 days for a new virtual machine is not a private cloud. It is traditional IT wearing a hypervisor. A setup only earns the name \"private cloud\" once it also lets its own users self-provision resources on demand, the same instant, no-approval experience a public cloud gives you, just restricted to one organization instead of the general public.",[28,55,56],{},"Even when it clears that bar, AWS's own comparison is candid about what a private cloud gives up: a single organization can rarely match the breadth of services, the pace of new features, or the economies of scale that a public provider spreads across millions of customers. Building your own version of a service like Amazon S3 gets you an S3-shaped bill, not S3 itself. That is why AWS argues private cloud fits a narrow case: very large organizations that already run their own data centers and have the infrastructure staff to operate them, not the default choice for most teams.",[23,58,60],{"id":59},"community-cloud-shared-by-not-sold-to","Community cloud: shared by, not sold to",[28,62,63],{},"NIST names a third exclusive model that gets far less attention: community cloud, infrastructure \"provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns,\" things like a common mission, security requirement, or compliance obligation. Unlike a public cloud, strangers cannot sign up. Unlike a private cloud, more than one organization shares it, as long as each belongs to the same vetted community.",[28,65,66],{},"You rarely meet a textbook community cloud in the wild, but government cloud regions come closest in practice: isolated environments built specifically for government agencies and their vetted contractors, who share the same compliance and security bar rather than being open to the general public. That is a useful real-world anchor for the definition, even though the more textbook case, research consortia or industry groups with a shared compliance need, stays niche.",[23,68,70],{"id":69},"comparing-the-3-models","Comparing the 3 models",[72,73,74,92],"table",{},[75,76,77],"thead",{},[78,79,80,83,86,89],"tr",{},[81,82],"th",{},[81,84,85],{},"Public cloud",[81,87,88],{},"Private cloud",[81,90,91],{},"Community cloud",[93,94,95,110,124,138],"tbody",{},[78,96,97,101,104,107],{},[98,99,100],"td",{},"Who owns the hardware",[98,102,103],{},"The provider",[98,105,106],{},"The organization, or a third party on its behalf",[98,108,109],{},"One or more organizations in the community, or a third party",[78,111,112,115,118,121],{},[98,113,114],{},"Who can use it",[98,116,117],{},"Anyone who pays",[98,119,120],{},"One organization only",[98,122,123],{},"A defined, vetted group sharing a concern",[78,125,126,129,132,135],{},[98,127,128],{},"Typical cost model",[98,130,131],{},"Pay-as-you-go, no upfront hardware cost",[98,133,134],{},"High upfront investment, ongoing operating cost",[98,136,137],{},"Usually shared among community members",[78,139,140,143,146,149],{},[98,141,142],{},"Where you'll meet it",[98,144,145],{},"AWS, Azure, Google Cloud",[98,147,148],{},"A bank's internal cloud platform",[98,150,151],{},"Government or research consortium environments",[23,153,155],{"id":154},"choosing-between-them","Choosing between them",[28,157,158],{},"Go back to the hospital and the startup. The startup has no compliance blocker and nothing of its own to protect, so public cloud is the obvious fit: no upfront cost, and elastic capacity from day one. The hospital's constraint is not cost or speed; it is that patient records cannot sit on hardware it does not control. A private cloud, expensive as it is to build and staff, is the model that satisfies that one non-negotiable requirement.",[28,160,161],{},"Watch for the same signal in any scenario you read. Phrases like \"dedicated,\" \"hardware we control,\" or a compliance rule that forbids shared infrastructure point at private cloud. Phrases like \"pay only for what you use,\" \"no upfront investment,\" or \"launch quickly with no infrastructure to manage\" point at public cloud. \"Shared by multiple organizations with the same compliance requirement\" is the community cloud signal, and it shows up rarely enough that when it does, it is almost always the deliberate answer, not a distractor.",[23,163,165],{"id":164},"where-this-leaves-you","Where this leaves you",[28,167,168],{},"The question that separates these 3 models is always the same: who owns the hardware, and who else is allowed to share it. Public cloud answers \"a provider, and anyone who pays.\" Private cloud answers \"one organization, no one else, and only if self-service is actually part of the deal.\" Community cloud answers \"a vetted group, and only that group.\" Real deployments rarely stop at picking one. The next lesson covers what happens when an organization combines them, connecting private infrastructure to a public cloud, or spreading workloads across more than one public provider, and why those 2 combinations are not the same thing.",{"title":170,"searchDepth":171,"depth":171,"links":172},"",3,[173,175,176,177,178,179,180],{"id":25,"depth":174,"text":26},2,{"id":36,"depth":174,"text":37},{"id":46,"depth":174,"text":47},{"id":59,"depth":174,"text":60},{"id":69,"depth":174,"text":70},{"id":154,"depth":174,"text":155},{"id":164,"depth":174,"text":165},"md",[],[13,14,15,16],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/01-public-and-private-clouds",{"passingScore":187,"questions":188},70,[189,195,201,206,216,221],{"question":190,"type":191,"options":192,"correctAnswer":85,"explanation":194},"A 3-person startup needs to launch a product in 6 weeks with no budget for servers or IT staff. Which deployment model fits this scenario best?","single",[88,91,85,193],"Traditional on-premises IT","Public cloud requires no upfront hardware investment and lets the startup pay only for what it uses from day one, which is exactly what a fast, cash-strapped launch needs. Private cloud demands the opposite, a large upfront investment and dedicated infrastructure staff, and community cloud only applies when several organizations share a specific compliance concern, which is not the case here.",{"question":196,"type":191,"options":197,"correctAnswer":199,"explanation":200},"A company virtualizes its own servers, but developers still have to file an IT ticket and wait 2 days for a new virtual machine. This setup qualifies as a private cloud.",[198,199],"True","False","A private cloud still has to clear the on-demand self-service bar from the NIST characteristics: users provision resources themselves, with no approval wait. A ticket-and-wait process fails that test no matter how much virtualization sits underneath it, which makes this setup traditional IT with a hypervisor, not a private cloud.",{"question":202,"type":191,"options":203,"correctAnswer":91,"explanation":205},"Which NIST deployment model is defined as infrastructure provisioned for the exclusive use of organizations that share a specific concern, such as a common compliance requirement, rather than a single organization or the general public?",[85,204,88,91],"Hybrid cloud","Community cloud sits between private and public: more than one organization shares it, but only organizations that belong to the same vetted community, unlike a public cloud open to anyone who pays. Hybrid cloud, covered in the next lesson, is a different idea entirely: combining 2 or more deployment models rather than defining a new one.",{"question":207,"type":208,"options":209,"correctAnswers":214,"explanation":215},"According to AWS's own comparison of public and private cloud, which of these are genuine advantages of public cloud? (Select all that apply.)","multiple",[210,211,212,213],"No upfront hardware investment","The provider handles maintenance and security of the underlying infrastructure","Complete control over the physical location of every server","Pay only for the capacity actually used",[210,211,213],"Public cloud removes the upfront hardware cost, shifts infrastructure maintenance and security to the provider, and bills based on metered usage, all advantages AWS highlights directly. Complete control over physical server location is a private cloud trait, not a public cloud one; public cloud customers deliberately give up that control in exchange for scale and cost efficiency.",{"question":217,"type":191,"options":218,"correctAnswer":88,"explanation":220},"A hospital's compliance officer requires that patient records never sit on shared, multi-tenant hardware, but the hospital's own IT platform lets clinicians self-provision new virtual machines instantly through a portal, with no approval wait. Which deployment model does this describe?",[88,85,91,219],"Traditional on-premises IT with no cloud characteristics","Dedicated, non-shared hardware controlled by a single organization is the defining trait of private cloud, and the instant self-service the scenario describes is what earns it the name cloud rather than just virtualized IT. Public cloud is ruled out by the multi-tenant restriction, and community cloud requires more than one organization sharing the infrastructure, which is not described here.",{"question":222,"type":191,"options":223,"correctAnswer":224,"explanation":228},"Per AWS's own guidance, which organizations are private cloud deployments typically best suited for?",[224,225,226,227],"Very large organizations that already run their own data centers and infrastructure teams","Small startups with no in-house IT staff","Any organization that wants slightly better security","Organizations with no compliance requirements at all","AWS is candid that a private cloud is hard to justify outside a narrow case: organizations large enough to already operate data centers and the staff to run them, since replicating a public provider's scale and service breadth privately is expensive and rarely worth it. A startup with no IT staff is the profile public cloud fits best, the opposite of this scenario.",{"title":7,"description":8},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/01-public-and-private-clouds","Q-XDVOffNTOcINp5PmeZIT8uxu_YHy2l43X925m-cek",{"locked":5,"reason":3,"meta":233,"item":242},{"title":234,"description":235,"isFree":5,"estimatedMinutes":236,"difficulty":11,"learningObjectives":237},"Hybrid and Multi-Cloud","How organizations connect private infrastructure to the public cloud, spread workloads across more than one provider, and why hybrid cloud and multi-cloud solve different problems despite getting used interchangeably.",17,[238,239,240,241],"Define hybrid cloud using the NIST framework and explain how it connects 2 or more distinct infrastructures","Define multi-cloud and distinguish it from hybrid cloud based on integration and infrastructure type","Explain why vendor lock-in and compliance requirements drive organizations toward hybrid or multi-cloud strategies","Evaluate a scenario to determine whether it describes hybrid cloud, multi-cloud, both, or neither",{"id":243,"title":234,"body":244,"description":235,"difficulty":11,"estimatedMinutes":236,"extension":181,"infographics":377,"isFree":5,"learningObjectives":388,"meta":389,"navigation":9,"path":390,"quiz":391,"seo":435,"stem":436,"__hash__":437},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/02-hybrid-and-multi-cloud.md",{"type":20,"value":245,"toc":370},[246,250,253,256,259,263,266,269,272,276,279,282,285,290,294,297,356,359,362,365,367],[23,247,249],{"id":248},"two-problems-two-different-fixes","Two problems, two different fixes",[28,251,252],{},"A regional bank keeps its core ledger on a mainframe in its own data center, because moving 40 years of transaction history and a strict regulator's audit trail is not something you do casually. But the bank also wants its new mobile app to run on infrastructure that can absorb a holiday shopping spike without buying servers it uses 3 days a year. That is one problem: connecting infrastructure you cannot leave with infrastructure you want to add.",[28,254,255],{},"A different company, a fast-growing social app, has already committed to a multi-year, multi-billion dollar contract with one cloud provider and watches that single contract dominate its infrastructure budget. Losing negotiating leverage, and being one contract dispute away from a painful renegotiation, is a different problem: depending on a single vendor for everything.",[28,257,258],{},"The deployment models from the previous lesson do not have a name for either fix on their own. Hybrid cloud and multi-cloud are what organizations build when public, private, and community cloud each solve part of the problem, but no single one solves all of it.",[23,260,262],{"id":261},"hybrid-cloud-2-infrastructures-bound-together","Hybrid cloud: 2 infrastructures, bound together",[28,264,265],{},"NIST defines a hybrid cloud as \"a composition of 2 or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability.\" Read that carefully: the pieces stay separate. The bank's mainframe does not become part of AWS, and AWS does not become part of the bank's data center. What connects them is a layer, built specifically to move data and workloads between the two, that makes the boundary as invisible as possible to the people using it.",[28,267,268],{},"That connective layer is a real product category, and several vendors sell exactly this. AWS Outposts extends AWS hardware, APIs, and services into a company's own data center, so a team can run the same tools on-premises and in the public cloud without learning 2 different platforms. Microsoft's Azure Arc and Azure Stack HCI do the equivalent for Azure: managing on-premises servers, Kubernetes clusters, and databases as if they were Azure resources, wherever they physically sit. In both cases, the point is portability, moving an application or a dataset across the boundary without rebuilding it.",[28,270,271],{},"Back to the bank: the ledger stays on the mainframe it cannot move, and the mobile app runs in the public cloud where it can absorb a traffic spike overnight. Hybrid cloud is what lets both halves work as one system instead of 2 unrelated ones, sharing identity, monitoring, and in some cases data, across the line between them.",[23,273,275],{"id":274},"multi-cloud-more-than-one-public-provider","Multi-cloud: more than one public provider",[28,277,278],{},"Multi-cloud means something narrower than it sounds: using public cloud services from 2 or more separate providers, AWS and Google Cloud, for instance, rather than committing everything to one. Google Cloud's own definition keeps it simple: an organization uses cloud computing services from at least 2 public providers to run its applications.",[28,280,281],{},"The social app from the opening is a real pattern, not a hypothetical. Snap Inc, the company behind Snapchat, committed to spend at least $2 billion with Google Cloud over 5 years starting in 2017, a contract so large that Snap's own IPO filing named it as a major financial risk. Snap's response was to add a second, separate commitment: at least $1 billion to AWS by the end of 2021, for what its filing called \"redundant infrastructure support.\" Snap's infrastructure today runs as microservices spread across both providers, so no single vendor's pricing, outage, or contract renewal can dictate every term.",[28,283,284],{},"Vendor lock-in is the main reason organizations go multi-cloud, but it is not the only one. Some services genuinely are stronger on one provider, so a team might run its data warehouse on one cloud and its machine learning pipeline on another to use each provider's strongest offering. Data residency rules in some countries require certain data to stay within that country's borders, and the fastest provider region there is not always the one a company already uses everywhere else.",[286,287],"infographic",{"alt":288,"slug":289},"A side-by-side diagram contrasting hybrid cloud, private infrastructure connected to one public cloud, with multi-cloud, multiple independent public cloud providers with no connection between them.","hybrid-and-multi-cloud-comparison",[23,291,293],{"id":292},"the-boundary-hybrid-or-multi-cloud-and-why-both-is-common","The boundary: hybrid or multi-cloud, and why \"both\" is common",[28,295,296],{},"Hybrid and multi-cloud answer different questions, and a scenario usually only tests one at a time.",[72,298,299,310],{},[75,300,301],{},[78,302,303,305,307],{},[81,304],{},[81,306,204],{},[81,308,309],{},"Multi-cloud",[93,311,312,323,334,345],{},[78,313,314,317,320],{},[98,315,316],{},"What's connected",[98,318,319],{},"A private or on-premises environment plus at least one public cloud",[98,321,322],{},"2 or more separate public cloud providers",[78,324,325,328,331],{},[98,326,327],{},"Integration",[98,329,330],{},"Bound together deliberately: shared APIs, identity, and data portability",[98,332,333],{},"Often independent; providers usually do not talk to each other",[78,335,336,339,342],{},[98,337,338],{},"Primary driver",[98,340,341],{},"Compliance, latency, or infrastructure you cannot retire",[98,343,344],{},"Avoiding vendor lock-in, using each provider's strongest service",[78,346,347,350,353],{},[98,348,349],{},"Real examples",[98,351,352],{},"AWS Outposts, Azure Arc, a bank's mainframe plus a cloud-hosted app",[98,354,355],{},"Snap Inc running microservices across AWS and Google Cloud",[28,357,358],{},"A company can be both at once, and increasingly is. Picture a hospital network again: patient records stay on private, on-premises hardware for compliance, the hybrid half, while its billing system runs on AWS and its telehealth video service runs on a different provider chosen for lower latency in certain regions, the multi-cloud half. Nothing about the definitions forces a company to pick a lane.",[28,360,361],{},"One trap worth naming directly: running workloads in 2 different regions of the same provider, 2 AWS regions, for example, is not multi-cloud. Multi-cloud specifically means separate providers. Running in multiple regions of one provider is a resilience technique within a single cloud, a different concept covered later in this course.",[28,363,364],{},"A second misconception: multi-cloud does not automatically mean an application survives a provider's outage. Spreading unrelated workloads across 2 providers, one team's app on AWS, a different team's app on Azure, reduces contract and pricing risk, but if a single application only runs on one of those providers, that application still goes down when that provider does. True cross-provider resilience means actively architecting one workload to run on more than one cloud at once, which is harder and rarer than multi-cloud adoption numbers suggest.",[23,366,165],{"id":164},[28,368,369],{},"Ask 2 questions, not one, before you label a setup. Does it include a private or on-premises piece connected to a public cloud? If yes, that is the hybrid half. Does it involve more than one separate public provider? If yes, that is the multi-cloud half. A setup can answer yes to both, one, or neither, and the label only matters because it tells you what problem the organization was actually solving: keeping something it cannot move, or refusing to depend on anyone it does not have to. The next topic leaves deployment models behind and turns to the question every one of these choices eventually runs into: what it actually costs.",{"title":170,"searchDepth":171,"depth":171,"links":371},[372,373,374,375,376],{"id":248,"depth":174,"text":249},{"id":261,"depth":174,"text":262},{"id":274,"depth":174,"text":275},{"id":292,"depth":174,"text":293},{"id":164,"depth":174,"text":165},[378],{"slug":289,"concept":379,"style":380,"aspectRatio":381,"labels":382},"A two-panel diagram side by side. The left panel, titled Hybrid Cloud, shows a private or on-premises server icon connected by a solid bidirectional arrow to a single public cloud icon, with a small label on the connecting arrow reading data and app portability. The right panel, titled Multi-Cloud, shows 3 separate public cloud provider icons, labeled generically rather than by brand, positioned side by side with no connecting arrows between them, each tied to a different, separate workload. A footer strip carries the one-sentence takeaway distinguishing the two.","diagram","16:9",[383,384,385,386,387],"Hybrid Cloud: private or on-premises infrastructure connected to a public cloud","The connection: standardized technology that moves data and applications across the boundary","Multi-Cloud: 2 or more separate public cloud providers, usually independent of each other","Each provider serves its own workload, with no automatic integration between them","Hybrid connects what has to stay in place; multi-cloud diversifies who provides the rest",[238,239,240,241],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/02-hybrid-and-multi-cloud",{"passingScore":187,"questions":392},[393,398,402,410,419,427],{"question":394,"type":191,"options":395,"correctAnswer":204,"explanation":397},"A regional bank keeps its 40-year-old transaction ledger on its own mainframe for regulatory reasons, but runs its new mobile app on AWS to absorb unpredictable traffic spikes, sharing identity and monitoring tools across both environments. What does this describe?",[309,91,204,396],"Public cloud only","Connecting a private, on-premises environment to a public cloud, and binding them together with shared tooling so data and workloads can move between them, is the definition of hybrid cloud. Multi-cloud specifically means multiple separate public providers, which is not what is described, since only one public cloud, AWS, appears here.",{"question":399,"type":191,"options":400,"correctAnswer":199,"explanation":401},"Running workloads in 2 different regions of the same cloud provider counts as multi-cloud.",[198,199],"Multi-cloud specifically means using 2 or more separate providers, such as AWS and Azure. Running in multiple regions of one provider is a resilience technique inside a single cloud, not multi-cloud, and exam-style scenarios use this exact wording as a trap.",{"question":403,"type":191,"options":404,"correctAnswer":406,"explanation":409},"Snap Inc added a second, separate cloud provider commitment after its Google Cloud contract became a major financial risk. What is the primary driver behind this kind of decision?",[405,406,407,408],"Meeting a data residency law","Avoiding dependence on a single vendor","Connecting on-premises hardware to the cloud","Reducing network latency for end users","Vendor lock-in, being financially and technically dependent on one provider's pricing and contract terms, is the most common driver behind a multi-cloud strategy. It is exactly what pushed Snap Inc to add a redundant AWS commitment alongside its existing Google Cloud spend. Data residency and latency are real reasons some organizations go multi-cloud too, but they were not the driver in Snap's case.",{"question":411,"type":208,"options":412,"correctAnswers":417,"explanation":418},"Which of these are true about multi-cloud, based on this lesson? (Select all that apply.)",[413,414,415,416],"It always means an application automatically survives if one provider has an outage","It means using public cloud services from 2 or more separate providers","A common driver is avoiding dependence on a single vendor's pricing and contracts","Providers in a multi-cloud setup are usually independent and do not automatically integrate with each other",[414,415,416],"Multi-cloud means spreading usage across 2 or more independent public providers, most often to avoid vendor lock-in, and those providers typically do not integrate with each other automatically. The one false statement is the automatic-resilience claim: an application still goes down with its provider unless it was specifically architected to run across more than one cloud at once, which most multi-cloud setups are not.",{"question":420,"type":191,"options":421,"correctAnswer":422,"explanation":426},"A hospital keeps patient records on private, on-premises hardware for compliance, runs its billing system on AWS, and runs its telehealth video service on a different provider chosen for lower regional latency. How would you best describe this hospital's overall cloud strategy?",[422,423,424,425],"Both hybrid and multi-cloud","Multi-cloud only","Hybrid only","Neither; this is traditional on-premises IT","The private records connected to a public cloud satisfy the hybrid half of the definition, and using 2 separate public providers for different services satisfies the multi-cloud half. Nothing in either definition prevents an organization from qualifying as both at once, which is increasingly the norm rather than the exception.",{"question":428,"type":191,"options":429,"correctAnswer":433,"explanation":434},"According to NIST's definition, what specifically has to be true for 2 or more cloud infrastructures to count as a hybrid cloud, rather than simply 2 unrelated systems a company happens to operate?",[430,431,432,433],"They must be owned by the same organization","They must both be public cloud infrastructures","They must run identical software versions","They must be bound together by technology that enables data and application portability","NIST's definition requires the pieces to remain distinct but be deliberately connected by standardized or proprietary technology that lets data and applications move between them, tools like AWS Outposts or Azure Arc. Simply operating a private data center and a separate AWS account with no integration between them is 2 unrelated systems, not a hybrid cloud.",{"title":234,"description":235},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/02-hybrid-and-multi-cloud","vUcflAyt2nSABthrpJ9Q3_VHTvO-A_-mK8ENTkCt0IM",{"locked":5,"reason":3,"meta":439,"item":447},{"title":440,"description":441,"isFree":5,"estimatedMinutes":10,"difficulty":11,"learningObjectives":442},"The 5 Characteristics of Cloud Computing","A deep dive into the 5 NIST essential characteristics, on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service, and how to use them as a test for whether a service is truly cloud computing.",[443,444,445,446],"Define each of the 5 NIST essential characteristics of cloud computing","Give a concrete example of each characteristic in action","Apply the 5 characteristics as a test to determine whether a service is truly cloud computing","Explain how virtualization enables resource pooling and rapid elasticity specifically",{"id":448,"title":440,"body":449,"description":441,"difficulty":11,"estimatedMinutes":10,"extension":181,"infographics":592,"isFree":5,"learningObjectives":593,"meta":594,"navigation":9,"path":595,"quiz":596,"seo":624,"stem":625,"__hash__":626},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing.md",{"type":20,"value":450,"toc":582},[451,455,458,461,465,468,471,475,478,481,485,488,491,495,498,501,505,508,511,515,518,572,575,579],[23,452,454],{"id":453},"the-5-question-test","The 5-question test",[28,456,457],{},"Two lessons ago, you learned the formal NIST definition of cloud computing. That definition names 5 essential characteristics, but only listed them by name. This lesson is where they earn their keep: each one is a specific, testable trait, and a service has to show all 5 before it genuinely counts as cloud computing rather than just \"a server somewhere else.\"",[28,459,460],{},"Treat this lesson as a checklist. When someone calls a service \"cloud,\" you can now ask, one by one, whether it actually has each trait.",[23,462,464],{"id":463},"_1-on-demand-self-service","1. On-demand self-service",[28,466,467],{},"You can provision computing resources, spinning up a server, requesting more storage, the moment you need them, without calling anyone or waiting for a person at the provider to act. You open a console, an API, or a command line, make the request, and it happens.",[28,469,470],{},"Contrast this with the hosting example from 2 lessons ago: emailing support and waiting a day for more RAM fails this test immediately. A real cloud service never puts a human approval step between your request and the resource showing up.",[23,472,474],{"id":473},"_2-broad-network-access","2. Broad network access",[28,476,477],{},"The service is reachable over standard networks, in practice the internet, from a mix of ordinary devices, laptops, phones, tablets, using standard tools like a web browser or a documented API, rather than requiring specialized hardware or a private connection only you have access to.",[28,479,480],{},"This is why you can manage a cloud account from your phone on a train and from a laptop at your desk with the same login, the same interface, and the same result. The service does not care what device asked.",[23,482,484],{"id":483},"_3-resource-pooling","3. Resource pooling",[28,486,487],{},"The provider serves many customers from the same underlying hardware using a multi-tenant model, and dynamically assigns resources to customers based on demand. Crucially, you usually do not know, and do not need to know, exactly which physical machine or which data center rack your workload is running on at any given moment.",[28,489,490],{},"This is the characteristic virtualization makes possible, covered in the previous lesson. A hypervisor slicing one physical server into many isolated virtual machines is exactly how a provider pools hardware across thousands of customers while keeping each customer's data and workload separated from the others.",[23,492,494],{"id":493},"_4-rapid-elasticity","4. Rapid elasticity",[28,496,497],{},"Capacity can scale outward, adding more resources, or inward, releasing resources, quickly, often automatically, to match real demand, and from the customer's perspective the pool of available resources looks close to unlimited.",[28,499,500],{},"Picture a retailer's website during a flash sale: traffic jumps 20 times its normal level for 3 hours, then falls back. A cloud setup can add servers to absorb that spike as it happens and remove them once the sale ends, so the retailer pays for that extra capacity only for the hours it actually ran. On-premises infrastructure, remember from the first lesson in this topic, cannot do this: it is stuck at whatever capacity you already bought.",[23,502,504],{"id":503},"_5-measured-service","5. Measured service",[28,506,507],{},"Cloud systems automatically meter resource usage, whether that is compute hours, gigabytes stored, or data transferred, and both the provider and the customer can see that usage transparently. This metering is what makes pay-as-you-go pricing possible: you are billed for what the system actually measured, not for a fixed allocation you may or may not have used.",[28,509,510],{},"You will cover the pricing models built on top of this metering, on-demand, reserved, and others, later in this domain's Cloud Economics topic.",[23,512,514],{"id":513},"running-the-checklist","Running the checklist",[28,516,517],{},"Put the 5 together and you get a fast test for any service someone calls \"cloud\":",[72,519,520,530],{},[75,521,522],{},[78,523,524,527],{},[81,525,526],{},"Characteristic",[81,528,529],{},"The question to ask",[93,531,532,540,548,556,564],{},[78,533,534,537],{},[98,535,536],{},"On-demand self-service",[98,538,539],{},"Can you get it yourself, right now, with no human approval?",[78,541,542,545],{},[98,543,544],{},"Broad network access",[98,546,547],{},"Can you reach it from any ordinary device over the internet?",[78,549,550,553],{},[98,551,552],{},"Resource pooling",[98,554,555],{},"Are you sharing underlying hardware with other customers, safely and invisibly?",[78,557,558,561],{},[98,559,560],{},"Rapid elasticity",[98,562,563],{},"Can capacity scale up and back down quickly to match real demand?",[78,565,566,569],{},[98,567,568],{},"Measured service",[98,570,571],{},"Are you billed based on metered, actual usage?",[28,573,574],{},"A service that is missing even one of these is not fully cloud computing under the NIST definition, no matter how it is marketed. The hosting example from earlier in this topic fails characteristic 1. A privately virtualized data center with a slow ticketing process for new VMs fails characteristics 1 and often 4. A service that only shows 3 of the 5 might still be useful, but calling it \"cloud\" is a marketing choice, not a technical one.",[23,576,578],{"id":577},"carrying-this-forward","Carrying this forward",[28,580,581],{},"You can now recognize real cloud computing by testing a service against these 5 traits instead of trusting a label. The next topic in this domain moves from what the cloud is to how it is deployed: public, private, community, and hybrid, the 4 models that describe who shares the pool with you.",{"title":170,"searchDepth":171,"depth":171,"links":583},[584,585,586,587,588,589,590,591],{"id":453,"depth":174,"text":454},{"id":463,"depth":174,"text":464},{"id":473,"depth":174,"text":474},{"id":483,"depth":174,"text":484},{"id":493,"depth":174,"text":494},{"id":503,"depth":174,"text":504},{"id":513,"depth":174,"text":514},{"id":577,"depth":174,"text":578},[],[443,444,445,446],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing",{"passingScore":187,"questions":597},[598,602,606,610,615,619],{"question":599,"type":191,"options":600,"correctAnswer":536,"explanation":601},"A team can request a new server through a console and have it running in minutes, with no approval from the provider's staff. Which characteristic does this describe?",[568,536,544,552],"On-demand self-service means you can provision resources yourself, without a phone call or a human approval step at the provider. Measured service is about metering usage for billing, and broad network access and resource pooling describe how the service is reached and how hardware is shared, not how quickly you can request it.",{"question":603,"type":191,"options":604,"correctAnswer":199,"explanation":605},"Broad network access means a cloud service must be reachable using specialized hardware that only the provider supplies.",[198,199],"Broad network access means the opposite: the service is reachable through standard mechanisms, ordinary laptops, phones, and tablets, using tools like a browser or a documented API, not specialized hardware.",{"question":607,"type":191,"options":608,"correctAnswer":552,"explanation":609},"Which characteristic depends directly on the virtualization technology covered in the previous lesson?",[568,544,552,536],"Resource pooling means a provider serves many customers from the same underlying hardware, and a hypervisor slicing one physical server into many isolated VMs is exactly the mechanism that makes that safe. The other characteristics depend more on how the service is accessed, requested, or billed than on the virtualization layer itself.",{"question":611,"type":208,"options":612,"correctAnswers":613,"explanation":614},"A retailer's website absorbs a 20-times traffic spike during a 3-hour flash sale by automatically adding servers, then releases them once the sale ends, paying only for the extra hours used. Which characteristics does this scenario demonstrate? (Select all that apply.)",[560,568,544,536],[560,568],"Scaling capacity up and back down to match a demand spike is rapid elasticity, and paying only for the extra hours actually used is measured service. The scenario does not describe how customers reach the site or how the retailer requested the servers, so it does not specifically demonstrate broad network access or on-demand self-service.",{"question":616,"type":191,"options":617,"correctAnswer":536,"explanation":618},"A company builds a private data center where developers still need to file an IT ticket and wait 2 days for a new virtual machine. Which characteristic does this setup most clearly fail?",[536,544,552,568],"A 2-day approval process is exactly the human interaction on-demand self-service is meant to remove. The setup could still have resource pooling and measured service if it virtualizes shared hardware and tracks usage, but the ticket-and-wait process fails self-service regardless.",{"question":620,"type":191,"options":621,"correctAnswer":622,"explanation":623},"What makes pay-as-you-go pricing possible in cloud computing?",[560,544,536,622],"Measured service, because usage is automatically tracked and billed accordingly","Measured service means the system automatically meters usage, compute hours, storage, data transfer, which is what lets a provider bill you for exactly what you consumed instead of a flat fee. Elasticity, network access, and self-service all shape how you use the cloud, but metering is what turns that usage into an accurate bill.",{"title":440,"description":441},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing","lq064IQgvgxRzu2RVaB8IIkOJIJqHblUyzaAfrgGpWE"]