Cloud Computing Basics

Cloud Computing Basics is where the whole course starts, because every later domain assumes you already know what "cloud" formally means. Before you can compare service models, weigh security tradeoffs, or read a pricing table, you need a working, testable definition of cloud computing itself, not just a feeling that it means "the internet" or "someone else's server."

This topic builds that definition in order: the problem that made the cloud necessary, the formal NIST definition, the virtualization technology underneath it, and the 5 specific traits that separate a real cloud service from a data center someone just calls one.

What This Topic Covers

• why cloud computing exists: the procurement delays, idle hardware, and upfront costs of traditional IT, and the 3 technologies (time-sharing, x86 virtualization, and affordable broadband) that had to converge before the cloud could replace it
• what cloud computing is: the official NIST definition of cloud computing, unpacked phrase by phrase, plus the shape of the larger model it introduces
• virtualization explained: how a hypervisor splits one physical server into many isolated virtual machines, and the difference between Type 1 and Type 2 hypervisors
• the 5 essential characteristics of cloud computing: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service, with the test each one gives you

Why It Matters

Without a precise definition, "cloud" becomes whatever a vendor's marketing wants it to mean. This topic gives you a 5-point test you can run against any service, on-demand self-service, broad network access, resource pooling, rapid elasticity, measured service, so you can tell whether something is genuinely cloud computing or just a remote server with a new name.

That test also explains the technology underneath the marketing. Once you understand what a hypervisor actually does, you can see exactly why a cloud provider can carve one physical machine into dozens of customer workloads safely, and exactly why a company that virtualizes its own servers still is not running a cloud unless it adds self-service and elasticity on top. Everything else in this course, deployment models, service models, pricing, security, builds on the vocabulary and the test this topic gives you.