[{"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-computing-basics-five-characteristics-of-cloud-computing-en":4,"next-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-computing-basics-five-characteristics-of-cloud-computing-en":215,"prev-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-computing-basics-five-characteristics-of-cloud-computing-en":421},null,{"locked":5,"reason":3,"meta":6,"item":16},false,{"title":7,"description":8,"isFree":5,"estimatedMinutes":9,"difficulty":10,"learningObjectives":11},"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.",16,"beginner",[12,13,14,15],"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":17,"title":7,"body":18,"description":8,"difficulty":10,"estimatedMinutes":9,"extension":173,"infographics":174,"isFree":5,"learningObjectives":175,"meta":176,"navigation":177,"path":178,"quiz":179,"seo":212,"stem":213,"__hash__":214},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing.md",{"type":19,"value":20,"toc":160},"minimark",[21,26,30,33,37,40,43,47,50,53,57,60,63,67,70,73,77,80,83,87,90,150,153,157],[22,23,25],"h2",{"id":24},"the-5-question-test","The 5-question test",[27,28,29],"p",{},"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.\"",[27,31,32],{},"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.",[22,34,36],{"id":35},"_1-on-demand-self-service","1. On-demand self-service",[27,38,39],{},"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.",[27,41,42],{},"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.",[22,44,46],{"id":45},"_2-broad-network-access","2. Broad network access",[27,48,49],{},"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.",[27,51,52],{},"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.",[22,54,56],{"id":55},"_3-resource-pooling","3. Resource pooling",[27,58,59],{},"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.",[27,61,62],{},"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.",[22,64,66],{"id":65},"_4-rapid-elasticity","4. Rapid elasticity",[27,68,69],{},"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.",[27,71,72],{},"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.",[22,74,76],{"id":75},"_5-measured-service","5. Measured service",[27,78,79],{},"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.",[27,81,82],{},"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.",[22,84,86],{"id":85},"running-the-checklist","Running the checklist",[27,88,89],{},"Put the 5 together and you get a fast test for any service someone calls \"cloud\":",[91,92,93,106],"table",{},[94,95,96],"thead",{},[97,98,99,103],"tr",{},[100,101,102],"th",{},"Characteristic",[100,104,105],{},"The question to ask",[107,108,109,118,126,134,142],"tbody",{},[97,110,111,115],{},[112,113,114],"td",{},"On-demand self-service",[112,116,117],{},"Can you get it yourself, right now, with no human approval?",[97,119,120,123],{},[112,121,122],{},"Broad network access",[112,124,125],{},"Can you reach it from any ordinary device over the internet?",[97,127,128,131],{},[112,129,130],{},"Resource pooling",[112,132,133],{},"Are you sharing underlying hardware with other customers, safely and invisibly?",[97,135,136,139],{},[112,137,138],{},"Rapid elasticity",[112,140,141],{},"Can capacity scale up and back down quickly to match real demand?",[97,143,144,147],{},[112,145,146],{},"Measured service",[112,148,149],{},"Are you billed based on metered, actual usage?",[27,151,152],{},"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.",[22,154,156],{"id":155},"carrying-this-forward","Carrying this forward",[27,158,159],{},"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":161,"searchDepth":162,"depth":162,"links":163},"",3,[164,166,167,168,169,170,171,172],{"id":24,"depth":165,"text":25},2,{"id":35,"depth":165,"text":36},{"id":45,"depth":165,"text":46},{"id":55,"depth":165,"text":56},{"id":65,"depth":165,"text":66},{"id":75,"depth":165,"text":76},{"id":85,"depth":165,"text":86},{"id":155,"depth":165,"text":156},"md",[],[12,13,14,15],{},true,"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing",{"passingScore":180,"questions":181},70,[182,187,193,197,203,207],{"question":183,"type":184,"options":185,"correctAnswer":114,"explanation":186},"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?","single",[146,114,122,130],"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":188,"type":184,"options":189,"correctAnswer":191,"explanation":192},"Broad network access means a cloud service must be reachable using specialized hardware that only the provider supplies.",[190,191],"True","False","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":194,"type":184,"options":195,"correctAnswer":130,"explanation":196},"Which characteristic depends directly on the virtualization technology covered in the previous lesson?",[146,122,130,114],"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":198,"type":199,"options":200,"correctAnswers":201,"explanation":202},"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.)","multiple",[138,146,122,114],[138,146],"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":204,"type":184,"options":205,"correctAnswer":114,"explanation":206},"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?",[114,122,130,146],"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":208,"type":184,"options":209,"correctAnswer":210,"explanation":211},"What makes pay-as-you-go pricing possible in cloud computing?",[138,122,114,210],"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":7,"description":8},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing","lq064IQgvgxRzu2RVaB8IIkOJIJqHblUyzaAfrgGpWE",{"locked":5,"reason":3,"meta":216,"item":224},{"title":217,"description":218,"isFree":177,"estimatedMinutes":9,"difficulty":10,"learningObjectives":219},"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.",[220,221,222,223],"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":225,"title":217,"body":226,"description":218,"difficulty":10,"estimatedMinutes":9,"extension":173,"infographics":376,"isFree":177,"learningObjectives":377,"meta":378,"navigation":177,"path":379,"quiz":380,"seo":418,"stem":419,"__hash__":420},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/01-public-and-private-clouds.md",{"type":19,"value":227,"toc":367},[228,232,235,238,242,245,248,252,255,258,261,265,268,271,275,350,354,357,360,364],[22,229,231],{"id":230},"who-owns-the-hardware-youre-using","Who owns the hardware you're using",[27,233,234],{},"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.",[27,236,237],{},"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.",[22,239,241],{"id":240},"public-cloud-one-provider-many-tenants","Public cloud: one provider, many tenants",[27,243,244],{},"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.",[27,246,247],{},"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.",[22,249,251],{"id":250},"private-cloud-one-organization-dedicated-hardware","Private cloud: one organization, dedicated hardware",[27,253,254],{},"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.",[27,256,257],{},"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.",[27,259,260],{},"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.",[22,262,264],{"id":263},"community-cloud-shared-by-not-sold-to","Community cloud: shared by, not sold to",[27,266,267],{},"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.",[27,269,270],{},"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.",[22,272,274],{"id":273},"comparing-the-3-models","Comparing the 3 models",[91,276,277,292],{},[94,278,279],{},[97,280,281,283,286,289],{},[100,282],{},[100,284,285],{},"Public cloud",[100,287,288],{},"Private cloud",[100,290,291],{},"Community cloud",[107,293,294,308,322,336],{},[97,295,296,299,302,305],{},[112,297,298],{},"Who owns the hardware",[112,300,301],{},"The provider",[112,303,304],{},"The organization, or a third party on its behalf",[112,306,307],{},"One or more organizations in the community, or a third party",[97,309,310,313,316,319],{},[112,311,312],{},"Who can use it",[112,314,315],{},"Anyone who pays",[112,317,318],{},"One organization only",[112,320,321],{},"A defined, vetted group sharing a concern",[97,323,324,327,330,333],{},[112,325,326],{},"Typical cost model",[112,328,329],{},"Pay-as-you-go, no upfront hardware cost",[112,331,332],{},"High upfront investment, ongoing operating cost",[112,334,335],{},"Usually shared among community members",[97,337,338,341,344,347],{},[112,339,340],{},"Where you'll meet it",[112,342,343],{},"AWS, Azure, Google Cloud",[112,345,346],{},"A bank's internal cloud platform",[112,348,349],{},"Government or research consortium environments",[22,351,353],{"id":352},"choosing-between-them","Choosing between them",[27,355,356],{},"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.",[27,358,359],{},"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.",[22,361,363],{"id":362},"where-this-leaves-you","Where this leaves you",[27,365,366],{},"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":161,"searchDepth":162,"depth":162,"links":368},[369,370,371,372,373,374,375],{"id":230,"depth":165,"text":231},{"id":240,"depth":165,"text":241},{"id":250,"depth":165,"text":251},{"id":263,"depth":165,"text":264},{"id":273,"depth":165,"text":274},{"id":352,"depth":165,"text":353},{"id":362,"depth":165,"text":363},[],[220,221,222,223],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/02-cloud-deployment-models/01-public-and-private-clouds",{"passingScore":180,"questions":381},[382,387,391,396,405,410],{"question":383,"type":184,"options":384,"correctAnswer":285,"explanation":386},"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?",[288,291,285,385],"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":388,"type":184,"options":389,"correctAnswer":191,"explanation":390},"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.",[190,191],"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":392,"type":184,"options":393,"correctAnswer":291,"explanation":395},"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?",[285,394,288,291],"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":397,"type":199,"options":398,"correctAnswers":403,"explanation":404},"According to AWS's own comparison of public and private cloud, which of these are genuine advantages of public cloud? (Select all that apply.)",[399,400,401,402],"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",[399,400,402],"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":406,"type":184,"options":407,"correctAnswer":288,"explanation":409},"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?",[288,285,291,408],"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":411,"type":184,"options":412,"correctAnswer":413,"explanation":417},"Per AWS's own guidance, which organizations are private cloud deployments typically best suited for?",[413,414,415,416],"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":217,"description":218},"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":422,"item":432},{"title":423,"description":424,"isFree":5,"estimatedMinutes":425,"difficulty":426,"learningObjectives":427},"Virtualization Explained","How a hypervisor splits one physical server into many isolated virtual machines, the difference between Type 1 and Type 2 hypervisors, and why virtualization alone does not make a system a cloud.",15,"intermediate",[428,429,430,431],"Explain how a hypervisor lets one physical server run several independent virtual machines","Distinguish Type 1 (bare metal) hypervisors from Type 2 (hosted) hypervisors","Connect virtualization to the cloud's resource pooling characteristic","Recognize why virtualization alone does not make a system a cloud",{"id":433,"title":423,"body":434,"description":424,"difficulty":426,"estimatedMinutes":425,"extension":173,"infographics":571,"isFree":5,"learningObjectives":583,"meta":584,"navigation":177,"path":585,"quiz":586,"seo":625,"stem":626,"__hash__":627},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained.md",{"type":19,"value":435,"toc":563},[436,440,443,447,450,453,457,460,468,474,534,539,543,546,550,553,556,560],[22,437,439],{"id":438},"one-box-many-computers","One box, many computers",[27,441,442],{},"Walk into a cloud provider's data center and you will find rows of physical servers, but the number of physical machines is nowhere close to the number of customers using them. A single physical server can host dozens of completely separate virtual machines at once, each one running its own operating system, each one convinced it has the whole computer to itself, each one invisible to the others. That trick, one physical machine appearing to be many independent ones, is virtualization, and it is the technology that makes the cloud's shared resource pool physically possible.",[22,444,446],{"id":445},"the-hypervisor-software-that-divides-a-computer","The hypervisor: software that divides a computer",[27,448,449],{},"The software that makes this work is called a hypervisor. A hypervisor sits between the physical hardware, CPU, memory, storage, network, and the virtual machines (VMs) running on top of it, and its job is to divide that hardware up and hand each VM its own slice, some CPU cycles, some RAM, some disk space, on a schedule the hypervisor controls.",[27,451,452],{},"From inside a VM, everything looks normal. The guest operating system boots, sees what looks like real memory and a real disk, and runs applications exactly as it would on physical hardware. It has no way to tell that its \"hardware\" is actually a slice of a much larger machine being shared with several other VMs. That illusion is the entire point: isolation. If one VM crashes or gets compromised, the others keep running undisturbed, because the hypervisor keeps them separated at all times.",[22,454,456],{"id":455},"two-ways-to-run-a-hypervisor","Two ways to run a hypervisor",[27,458,459],{},"Not all hypervisors sit in the same place. There are 2 types, and the difference matters for where each one gets used.",[27,461,462,463,467],{},"A ",[464,465,466],"strong",{},"Type 1 hypervisor",", also called bare metal, installs directly on the physical hardware and takes the place of a traditional operating system. It talks to the CPU and memory directly, with nothing in between. Because there is no host operating system competing for resources, Type 1 hypervisors are fast and are the kind you find running production workloads in data centers and cloud platforms. VMware vSphere, Microsoft Hyper-V, and KVM are examples.",[27,469,462,470,473],{},[464,471,472],{},"Type 2 hypervisor",", also called hosted, installs as an ordinary application on top of a regular operating system, the same way you would install a web browser. It has to ask that host operating system for CPU time and memory rather than talking to the hardware directly, which adds a layer of overhead. That overhead is a reasonable trade for convenience: Type 2 hypervisors are simple to install and use, which is why developers use them to test software across multiple operating systems on a single laptop. VMware Workstation and Oracle VirtualBox are examples.",[91,475,476,488],{},[94,477,478],{},[97,479,480,482,485],{},[100,481],{},[100,483,484],{},"Type 1 (Bare Metal)",[100,486,487],{},"Type 2 (Hosted)",[107,489,490,501,512,523],{},[97,491,492,495,498],{},[112,493,494],{},"Runs on",[112,496,497],{},"Physical hardware directly",[112,499,500],{},"A host operating system",[97,502,503,506,509],{},[112,504,505],{},"Performance",[112,507,508],{},"Higher, no host OS overhead",[112,510,511],{},"Lower, shares resources with the host OS",[97,513,514,517,520],{},[112,515,516],{},"Typical use",[112,518,519],{},"Data centers, cloud platforms, production workloads",[112,521,522],{},"Personal computers, developer testing, virtual desktops",[97,524,525,528,531],{},[112,526,527],{},"Examples",[112,529,530],{},"VMware vSphere, Microsoft Hyper-V, KVM",[112,532,533],{},"VMware Workstation, Oracle VirtualBox",[535,536],"infographic",{"alt":537,"slug":538},"Diagram comparing a Type 1 bare-metal hypervisor running directly on hardware with a Type 2 hosted hypervisor running as an application on top of a host operating system, both hosting multiple isolated virtual machines.","virtualization-explained-hypervisor-layers",[22,540,542],{"id":541},"why-this-made-the-clouds-resource-pool-possible","Why this made the cloud's resource pool possible",[27,544,545],{},"Go back to the NIST definition from the last lesson: \"a shared pool of configurable computing resources.\" Virtualization is the mechanism that makes that pool safely shareable. Without it, a provider would have to give each customer a dedicated physical machine, which is exactly the inefficient, one-customer-per-box model the cloud replaced. With it, a provider can carve one powerful physical server into dozens of VMs, sell each one to a different customer, and reclaim and reuse that capacity the moment a customer releases it. Rapid provisioning, spinning up a new VM in minutes, and resource pooling, many customers sharing hardware safely, both trace back to this one piece of software.",[22,547,549],{"id":548},"the-boundary-virtualized-is-not-the-same-as-cloud","The boundary: virtualized is not the same as cloud",[27,551,552],{},"Here is where it is easy to overreach. A company that installs a Type 1 hypervisor on its own servers and runs 10 VMs in its own data center has virtualized its infrastructure, but it has not necessarily built a cloud. If a developer still has to file an IT ticket and wait 2 days for someone to manually create a new VM, that setup fails the \"on-demand self-service\" and \"rapidly provisioned\" parts of the definition you learned in the last lesson, even though the underlying technology is identical to what a cloud provider uses.",[27,554,555],{},"Virtualization is necessary for cloud computing at the scale you see today, but it is not sufficient by itself. The cloud adds self-service provisioning, metering, and elasticity on top of virtualized hardware. You will see this exact distinction again once you reach private cloud deployments later in this domain, since a private cloud is what you get when an organization adds those missing pieces to its own virtualized infrastructure.",[22,557,559],{"id":558},"what-comes-next","What comes next",[27,561,562],{},"You now know the mechanism behind the shared pool: a hypervisor slicing physical hardware into isolated virtual machines. The next lesson names the 5 specific, testable traits, on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service, that separate a merely virtualized system from a true cloud.",{"title":161,"searchDepth":162,"depth":162,"links":564},[565,566,567,568,569,570],{"id":438,"depth":165,"text":439},{"id":445,"depth":165,"text":446},{"id":455,"depth":165,"text":456},{"id":541,"depth":165,"text":542},{"id":548,"depth":165,"text":549},{"id":558,"depth":165,"text":559},[572],{"slug":538,"concept":573,"style":574,"aspectRatio":575,"labels":576},"A two-panel side-by-side diagram. The left panel, labeled Type 1 (Bare Metal), shows a hypervisor bar sitting directly on a hardware bar, with 3 VM boxes stacked on top of the hypervisor. The right panel, labeled Type 2 (Hosted), shows a host OS bar on top of the hardware bar, a hypervisor bar on top of that, and 2 VM boxes on top of the hypervisor, one layer taller than the left panel to show the extra indirection. Each VM box is captioned as an isolated guest OS plus apps. A short example line sits under each panel naming real hypervisors of that type. A footer strip carries the takeaway line.","diagram","16:9",[577,578,579,580,581,582],"Type 1, Bare Metal: hypervisor runs directly on hardware","Type 2, Hosted: hypervisor runs as an app on the host OS","VM: guest OS plus apps, isolated from other VMs","Examples: VMware vSphere, Microsoft Hyper-V, KVM (Type 1)","Examples: VMware Workstation, Oracle VirtualBox (Type 2)","Every VM believes it owns a whole computer. The hypervisor decides how much of the real one it actually gets",[428,429,430,431],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained",{"passingScore":180,"questions":587},[588,596,600,608,617],{"question":589,"type":184,"options":590,"correctAnswer":592,"explanation":595},"What is the main job of a hypervisor?",[591,592,593,594],"To connect a data center to the internet","To divide a physical machine's hardware among several isolated virtual machines","To replace the need for physical servers entirely","To back up data to another location","A hypervisor sits between the physical hardware and the virtual machines running on top of it, dividing CPU, memory, storage, and network access among them while keeping each VM isolated. It does not connect a data center to the internet or eliminate the need for physical servers, since the hardware is still what the VMs ultimately run on.",{"question":597,"type":184,"options":598,"correctAnswer":191,"explanation":599},"A virtual machine's guest operating system can normally tell that it is sharing hardware with other virtual machines.",[190,191],"Isolation is the point of virtualization: each VM sees what looks like dedicated hardware and has no way to detect the other VMs sharing the same physical machine. If a VM could see or affect its neighbors, a crash or compromise in one VM could spread to others, which would defeat the purpose.",{"question":601,"type":184,"options":602,"correctAnswer":605,"explanation":607},"A team needs to run production workloads for thousands of customers in a data center with maximum performance. Which hypervisor type fits this scenario?",[603,604,605,606],"Type 2, because it is easier to install","Neither type, since data centers do not use hypervisors","Type 1, because it runs directly on the hardware with no host OS overhead","Type 2, because it supports more operating systems","Type 1 hypervisors run directly on the physical hardware without a host operating system competing for resources, which gives them the performance production data centers and cloud platforms need. Type 2 hypervisors add a layer of overhead that suits personal and test use better than large-scale production.",{"question":609,"type":199,"options":610,"correctAnswers":615,"explanation":616},"Which of these are examples of Type 1 (bare metal) hypervisors? (Select all that apply.)",[611,612,613,614],"VMware vSphere","Oracle VirtualBox","Microsoft Hyper-V","VMware Workstation",[611,613],"VMware vSphere and Microsoft Hyper-V run directly on physical hardware, making them Type 1 hypervisors. Oracle VirtualBox and VMware Workstation both install as applications on top of a host operating system, which makes them Type 2 hypervisors.",{"question":618,"type":184,"options":619,"correctAnswer":623,"explanation":624},"A company virtualizes its own servers with a Type 1 hypervisor, but developers must file an IT ticket and wait 2 days for a new VM. Why does this setup fail to qualify as cloud computing, even though it uses the same core technology as a cloud provider?",[620,621,622,623],"It uses the wrong type of hypervisor","It cannot run more than one VM","It does not use physical hardware","It lacks on-demand self-service and rapid provisioning","Virtualization is necessary for cloud computing but not sufficient by itself. This setup uses the identical technology a cloud provider uses, but a 2-day ticket process fails the on-demand self-service and rapid provisioning requirements from the NIST definition, which is what actually separates a cloud from a merely virtualized data center.",{"title":423,"description":424},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained","Uhlqdb9p6etQenQ9H6wDpvswNtnvX-GDxAORP0g1OAw"]