Picture a community allotment. You do not buy the land, lay the water mains, or build the shed. You rent a plot, turn the tap on when you need water, and pay only for what you use. When the season ends, you hand the plot back. The cloud is that allotment for computing: you rent compute and storage by the second from a provider’s data centres instead of buying and running your own servers.

Why it changed who gets to build

Before the cloud, running a real application meant buying servers, hosting them somewhere, powering and cooling them, and paying for all of it whether or not anyone used your app. The cloud turned that fixed, up-front cost into a small, on-demand one. You start a server in seconds, pay for the minutes it runs, and turn it off when you are done. That is the reason a single person today can run systems that used to need a whole team and a data centre.

The widely used reference definition, from the US National Institute of Standards and Technology, lists five characteristics of cloud computing: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. In plain words: you help yourself, from anywhere, to a shared pool that grows and shrinks with your need, and you are billed by what you measure.

The trade you are making

Renting is not free of trade-offs. You give up some control and you depend on a provider, which is why where you rent (the region) and who you rent from (the provider) are real decisions, not afterthoughts. A system that can move between providers is far more resilient than one wired to a single vendor. Keep that in mind from the first day, not the day a provider changes the rules.

Further reading

Sources

  1. National Institute of Standards and Technology. “The NIST Definition of Cloud Computing” (SP 800-145). https://csrc.nist.gov/publications/detail/sp/800-145/final
  2. AWS. “What is cloud computing?” https://aws.amazon.com/what-is-cloud-computing/