[{"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-virtualization-explained-en":4,"prev-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-computing-basics-virtualization-explained-en":231,"next-cloud-computing-fundamentals-cloud-concepts-and-economics-cloud-computing-basics-virtualization-explained-en":383},null,{"locked":5,"reason":3,"meta":6,"item":16},false,{"title":7,"description":8,"isFree":5,"estimatedMinutes":9,"difficulty":10,"learningObjectives":11},"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",[12,13,14,15],"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":17,"title":7,"body":18,"description":8,"difficulty":10,"estimatedMinutes":9,"extension":167,"infographics":168,"isFree":5,"learningObjectives":180,"meta":181,"navigation":182,"path":183,"quiz":184,"seo":228,"stem":229,"__hash__":230},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained.md",{"type":19,"value":20,"toc":156},"minimark",[21,26,30,34,37,40,44,47,55,61,127,132,136,139,143,146,149,153],[22,23,25],"h2",{"id":24},"one-box-many-computers","One box, many computers",[27,28,29],"p",{},"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.",[22,31,33],{"id":32},"the-hypervisor-software-that-divides-a-computer","The hypervisor: software that divides a computer",[27,35,36],{},"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.",[27,38,39],{},"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.",[22,41,43],{"id":42},"two-ways-to-run-a-hypervisor","Two ways to run a hypervisor",[27,45,46],{},"Not all hypervisors sit in the same place. There are 2 types, and the difference matters for where each one gets used.",[27,48,49,50,54],{},"A ",[51,52,53],"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.",[27,56,49,57,60],{},[51,58,59],{},"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.",[62,63,64,79],"table",{},[65,66,67],"thead",{},[68,69,70,73,76],"tr",{},[71,72],"th",{},[71,74,75],{},"Type 1 (Bare Metal)",[71,77,78],{},"Type 2 (Hosted)",[80,81,82,94,105,116],"tbody",{},[68,83,84,88,91],{},[85,86,87],"td",{},"Runs on",[85,89,90],{},"Physical hardware directly",[85,92,93],{},"A host operating system",[68,95,96,99,102],{},[85,97,98],{},"Performance",[85,100,101],{},"Higher, no host OS overhead",[85,103,104],{},"Lower, shares resources with the host OS",[68,106,107,110,113],{},[85,108,109],{},"Typical use",[85,111,112],{},"Data centers, cloud platforms, production workloads",[85,114,115],{},"Personal computers, developer testing, virtual desktops",[68,117,118,121,124],{},[85,119,120],{},"Examples",[85,122,123],{},"VMware vSphere, Microsoft Hyper-V, KVM",[85,125,126],{},"VMware Workstation, Oracle VirtualBox",[128,129],"infographic",{"alt":130,"slug":131},"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",[22,133,135],{"id":134},"why-this-made-the-clouds-resource-pool-possible","Why this made the cloud's resource pool possible",[27,137,138],{},"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.",[22,140,142],{"id":141},"the-boundary-virtualized-is-not-the-same-as-cloud","The boundary: virtualized is not the same as cloud",[27,144,145],{},"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.",[27,147,148],{},"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.",[22,150,152],{"id":151},"what-comes-next","What comes next",[27,154,155],{},"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":157,"searchDepth":158,"depth":158,"links":159},"",3,[160,162,163,164,165,166],{"id":24,"depth":161,"text":25},2,{"id":32,"depth":161,"text":33},{"id":42,"depth":161,"text":43},{"id":134,"depth":161,"text":135},{"id":141,"depth":161,"text":142},{"id":151,"depth":161,"text":152},"md",[169],{"slug":131,"concept":170,"style":171,"aspectRatio":172,"labels":173},"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",[174,175,176,177,178,179],"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",[12,13,14,15],{},true,"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained",{"passingScore":185,"questions":186},70,[187,196,202,210,220],{"question":188,"type":189,"options":190,"correctAnswer":192,"explanation":195},"What is the main job of a hypervisor?","single",[191,192,193,194],"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":197,"type":189,"options":198,"correctAnswer":200,"explanation":201},"A virtual machine's guest operating system can normally tell that it is sharing hardware with other virtual machines.",[199,200],"True","False","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":203,"type":189,"options":204,"correctAnswer":207,"explanation":209},"A team needs to run production workloads for thousands of customers in a data center with maximum performance. Which hypervisor type fits this scenario?",[205,206,207,208],"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":211,"type":212,"options":213,"correctAnswers":218,"explanation":219},"Which of these are examples of Type 1 (bare metal) hypervisors? (Select all that apply.)","multiple",[214,215,216,217],"VMware vSphere","Oracle VirtualBox","Microsoft Hyper-V","VMware Workstation",[214,216],"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":221,"type":189,"options":222,"correctAnswer":226,"explanation":227},"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?",[223,224,225,226],"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":7,"description":8},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/03-virtualization-explained","Uhlqdb9p6etQenQ9H6wDpvswNtnvX-GDxAORP0g1OAw",{"locked":5,"reason":3,"meta":232,"item":242},{"title":233,"description":234,"isFree":5,"estimatedMinutes":235,"difficulty":236,"learningObjectives":237},"What Is Cloud Computing?","The official NIST definition of cloud computing, unpacked phrase by phrase, and the test it gives you for telling a real cloud service apart from a data center someone just calls one.",14,"beginner",[238,239,240,241],"State the NIST definition of cloud computing","Explain what each phrase in the definition actually requires of a real cloud service","List the 5 essential characteristics, 3 service models, and 4 deployment models the definition names","Identify when a hosted server does not qualify as cloud computing",{"id":243,"title":233,"body":244,"description":234,"difficulty":236,"estimatedMinutes":235,"extension":167,"infographics":337,"isFree":5,"learningObjectives":338,"meta":339,"navigation":182,"path":340,"quiz":341,"seo":380,"stem":381,"__hash__":382},"courses/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/02-what-is-cloud-computing.md",{"type":19,"value":245,"toc":330},[246,250,253,256,260,263,266,269,272,275,278,281,285,288,310,313,317,320,323,327],[22,247,249],{"id":248},"a-definition-that-has-to-do-real-work","A definition that has to do real work",[27,251,252],{},"\"The cloud\" gets used so loosely that it can mean almost anything: a file synced to a phone, a website hosted somewhere else, an email account you did not have to install software for. That looseness is a problem the moment you need to tell whether a specific service actually is cloud computing, or just something running on someone else's server. You need a definition precise enough to test a service against, not just a feeling.",[27,254,255],{},"The definition the industry actually uses comes from the U.S. National Institute of Standards and Technology (NIST), published in Special Publication 800-145. It is vendor-neutral: NIST does not sell cloud services, so its definition describes the model itself rather than any one provider's marketing.",[22,257,259],{"id":258},"the-nist-definition-phrase-by-phrase","The NIST definition, phrase by phrase",[27,261,262],{},"Here is the full definition:",[27,264,265],{},"\"Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.\"",[27,267,268],{},"That is a dense sentence, so unpack it piece by piece.",[27,270,271],{},"\"Ubiquitous, convenient, on-demand network access\" means you reach the service over a network, almost always the internet, from ordinary devices, whenever you want, without arranging access in advance.",[27,273,274],{},"\"A shared pool of configurable computing resources\" means many customers draw from the same underlying hardware, servers, storage, networking, rather than each customer owning a dedicated machine. \"Configurable\" matters here: you are not just handed a fixed slice, you can shape what you get to fit your needs.",[27,276,277],{},"\"Rapidly provisioned and released\" means capacity appears when you ask for it and disappears when you are done with it, on the order of minutes, not the weeks you saw in the previous lesson.",[27,279,280],{},"\"With minimal management effort or service provider interaction\" means you do not file a request and wait for a human at the provider to act on it. You configure it yourself, through a console, an API, or a command line.",[22,282,284],{"id":283},"the-shape-of-the-full-model","The shape of the full model",[27,286,287],{},"NIST's definition is really the headline for a larger model with 3 parts, each covered in its own place in this course:",[289,290,291,298,304],"ul",{},[292,293,294,297],"li",{},[51,295,296],{},"5 essential characteristics",", the specific, testable traits every real cloud service has to exhibit. The next lesson walks through all 5 in depth.",[292,299,300,303],{},[51,301,302],{},"3 service models",", IaaS, PaaS, and SaaS, which describe how much of the technology stack the provider manages for you versus how much you manage yourself. You will cover these in the Cloud Service Models topic later in this course.",[292,305,306,309],{},[51,307,308],{},"4 deployment models",", public, private, community, and hybrid, which describe who the infrastructure is shared with. You will cover these in the next topic, Cloud Deployment Models.",[27,311,312],{},"You do not need to memorize those lists yet. What matters here is the shape: a cloud service is defined by characteristics it must have, not by a single technology or a single company.",[22,314,316],{"id":315},"the-boundary-that-trips-people-up","The boundary that trips people up",[27,318,319],{},"Here is the misconception worth naming directly: a server you did not buy is not automatically \"cloud.\" A traditional web host that racks a physical server for you, gives you SSH access, and requires you to email support and wait a day whenever you want more RAM is not cloud computing, even though it is remote and even though someone else owns the hardware. It fails the definition on \"on-demand\" and \"minimal service provider interaction,\" because a human has to act before you get more capacity.",[27,321,322],{},"Contrast that with a service where you open a console, request more capacity, and have it within minutes, with no email, no ticket, no wait. That gap, self-service versus request-and-wait, is the practical test you can apply to almost any service someone calls \"cloud\" to check whether it actually earns the label.",[22,324,326],{"id":325},"carrying-this-forward","Carrying this forward",[27,328,329],{},"You now have the test: a real cloud service is on-demand, self-service, network-accessible, drawn from a shared and elastic resource pool, and billed for what you actually use. The next lesson slows down on each of those 5 traits individually, because they are exactly what a genuine architecture decision, or an exam question, will ask you to recognize.",{"title":157,"searchDepth":158,"depth":158,"links":331},[332,333,334,335,336],{"id":248,"depth":161,"text":249},{"id":258,"depth":161,"text":259},{"id":283,"depth":161,"text":284},{"id":315,"depth":161,"text":316},{"id":325,"depth":161,"text":326},[],[238,239,240,241],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/02-what-is-cloud-computing",{"passingScore":185,"questions":342},[343,351,355,363,372],{"question":344,"type":189,"options":345,"correctAnswer":348,"explanation":350},"Which organization publishes the vendor-neutral definition of cloud computing used throughout this course?",[346,347,348,349],"Amazon Web Services","The International Organization for Standardization","The U.S. National Institute of Standards and Technology (NIST)","Microsoft","NIST is a U.S. government standards body with no cloud services to sell, so its SP 800-145 definition describes the model itself rather than any one vendor's product. AWS and Microsoft are cloud providers, not standards bodies, and while ISO publishes its own technology standards, this specific definition originates with NIST.",{"question":352,"type":189,"options":353,"correctAnswer":200,"explanation":354},"According to the NIST definition, a real cloud service requires a person at the provider to manually approve most capacity requests.",[199,200],"The definition specifically calls for capabilities that are provisioned with minimal management effort or service provider interaction, meaning you provision resources yourself rather than waiting on a human at the provider. A service that requires a support ticket for every change fails this part of the definition.",{"question":356,"type":189,"options":357,"correctAnswer":359,"explanation":362},"A hosting company racks a physical server for a customer, provides SSH access, and requires an email to support (with a 1-day wait) whenever the customer wants more RAM. Why does this NOT qualify as cloud computing under the NIST definition?",[358,359,360,361],"It uses physical hardware instead of software","It fails the requirement for rapid provisioning with minimal service provider interaction","It does not use the internet","It only serves one customer","The definition requires resources to be provisioned quickly with minimal interaction with the provider's staff. Waiting a day for a human to manually add RAM violates that requirement, even though the server is remote and someone else owns the hardware.",{"question":364,"type":212,"options":365,"correctAnswers":370,"explanation":371},"According to the NIST model, which 3 categories break down the full cloud computing model beyond the core definition? (Select all that apply.)",[366,367,368,369],"Essential characteristics","Service models","Programming languages","Deployment models",[366,367,369],"NIST's model breaks down into 5 essential characteristics, 3 service models (IaaS, PaaS, SaaS), and 4 deployment models (public, private, community, hybrid). Programming languages are not part of the definitional model, since cloud computing is defined by delivery characteristics, not by what code runs on it.",{"question":373,"type":189,"options":374,"correctAnswer":378,"explanation":379},"In the phrase 'a shared pool of configurable computing resources,' what does 'configurable' add to the meaning?",[375,376,377,378],"Only the provider can adjust your resources","You get a fixed, unchangeable slice of the pool","Configuration only applies to networking","You can shape how much of each resource, like storage or compute, you draw from the pool, rather than receiving a one-size-fits-all allocation","Configurable means the resource pool is not a single fixed package. You choose how much compute, storage, or other capacity you need, and that shape can change over time as your needs change.",{"title":233,"description":234},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/02-what-is-cloud-computing","U7y35nu3VXw3x3qCDrUI0FpvIBvE4tpNqiU40phdsNU",{"locked":5,"reason":3,"meta":384,"item":393},{"title":385,"description":386,"isFree":5,"estimatedMinutes":387,"difficulty":236,"learningObjectives":388},"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,[389,390,391,392],"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":394,"title":385,"body":395,"description":386,"difficulty":236,"estimatedMinutes":387,"extension":167,"infographics":536,"isFree":5,"learningObjectives":537,"meta":538,"navigation":182,"path":539,"quiz":540,"seo":568,"stem":569,"__hash__":570},"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":396,"toc":526},[397,401,404,407,411,414,417,421,424,427,431,434,437,441,444,447,451,454,457,461,464,518,521,523],[22,398,400],{"id":399},"the-5-question-test","The 5-question test",[27,402,403],{},"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.\"",[27,405,406],{},"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.",[22,408,410],{"id":409},"_1-on-demand-self-service","1. On-demand self-service",[27,412,413],{},"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.",[27,415,416],{},"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.",[22,418,420],{"id":419},"_2-broad-network-access","2. Broad network access",[27,422,423],{},"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.",[27,425,426],{},"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.",[22,428,430],{"id":429},"_3-resource-pooling","3. Resource pooling",[27,432,433],{},"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.",[27,435,436],{},"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.",[22,438,440],{"id":439},"_4-rapid-elasticity","4. Rapid elasticity",[27,442,443],{},"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.",[27,445,446],{},"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.",[22,448,450],{"id":449},"_5-measured-service","5. Measured service",[27,452,453],{},"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.",[27,455,456],{},"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.",[22,458,460],{"id":459},"running-the-checklist","Running the checklist",[27,462,463],{},"Put the 5 together and you get a fast test for any service someone calls \"cloud\":",[62,465,466,476],{},[65,467,468],{},[68,469,470,473],{},[71,471,472],{},"Characteristic",[71,474,475],{},"The question to ask",[80,477,478,486,494,502,510],{},[68,479,480,483],{},[85,481,482],{},"On-demand self-service",[85,484,485],{},"Can you get it yourself, right now, with no human approval?",[68,487,488,491],{},[85,489,490],{},"Broad network access",[85,492,493],{},"Can you reach it from any ordinary device over the internet?",[68,495,496,499],{},[85,497,498],{},"Resource pooling",[85,500,501],{},"Are you sharing underlying hardware with other customers, safely and invisibly?",[68,503,504,507],{},[85,505,506],{},"Rapid elasticity",[85,508,509],{},"Can capacity scale up and back down quickly to match real demand?",[68,511,512,515],{},[85,513,514],{},"Measured service",[85,516,517],{},"Are you billed based on metered, actual usage?",[27,519,520],{},"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.",[22,522,326],{"id":325},[27,524,525],{},"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":157,"searchDepth":158,"depth":158,"links":527},[528,529,530,531,532,533,534,535],{"id":399,"depth":161,"text":400},{"id":409,"depth":161,"text":410},{"id":419,"depth":161,"text":420},{"id":429,"depth":161,"text":430},{"id":439,"depth":161,"text":440},{"id":449,"depth":161,"text":450},{"id":459,"depth":161,"text":460},{"id":325,"depth":161,"text":326},[],[389,390,391,392],{},"/courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing",{"passingScore":185,"questions":541},[542,546,550,554,559,563],{"question":543,"type":189,"options":544,"correctAnswer":482,"explanation":545},"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?",[514,482,490,498],"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":547,"type":189,"options":548,"correctAnswer":200,"explanation":549},"Broad network access means a cloud service must be reachable using specialized hardware that only the provider supplies.",[199,200],"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":551,"type":189,"options":552,"correctAnswer":498,"explanation":553},"Which characteristic depends directly on the virtualization technology covered in the previous lesson?",[514,490,498,482],"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":555,"type":212,"options":556,"correctAnswers":557,"explanation":558},"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.)",[506,514,490,482],[506,514],"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":560,"type":189,"options":561,"correctAnswer":482,"explanation":562},"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?",[482,490,498,514],"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":564,"type":189,"options":565,"correctAnswer":566,"explanation":567},"What makes pay-as-you-go pricing possible in cloud computing?",[506,490,482,566],"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":385,"description":386},"courses/cloud-computing-fundamentals/en/domains/01-cloud-concepts-and-economics/01-cloud-computing-basics/04-five-characteristics-of-cloud-computing","lq064IQgvgxRzu2RVaB8IIkOJIJqHblUyzaAfrgGpWE"]