Lesson 1 / 26

What is Cloud Computing?

Renting compute, storage, and networking instead of owning hardware.

The core idea

Cloud computing means renting compute, storage, and networking from a provider over the internet, paying only for what you use, instead of buying and maintaining your own servers.

IaaS, PaaS, SaaS at a glance

IaaS gives raw building blocks — servers, storage, networks (e.g. EC2). PaaS manages the runtime for you, you just deploy code (e.g. Elastic Beanstalk). SaaS is a finished application you simply use (e.g. Gmail). AWS mostly sits at IaaS/PaaS.

Electricity, not a generator

Before the grid, every factory ran its own generator. The cloud is like the electricity grid: you plug in and pay per unit used, instead of owning, maintaining, and over-sizing your own power plant.

Pay-as-you-go mindset

Think in usage, not capacity you pre-bought. Scale up during load, scale down after — the whole point of the cloud is not paying for idle hardware.