EC2: Virtual Servers

Definition: Amazon EC2 (Elastic Compute Cloud) lets you rent virtual servers — called instances — in the cloud. It is the classic way to run an application or website on AWS.

What you control

• Instance type — how much CPU and memory (from tiny to enormous)
• Operating system — Linux or Windows, via an image called an AMI
• Storage — attach disk volumes (EBS)
• Networking & security — which ports are open, via security groups

Elastic = it scales

The "Elastic" in EC2 means you can add or remove instances as demand changes, and even do it automatically with Auto Scaling. Pay only while an instance runs.

A taste of the CLI

aws ec2 describe-instances
aws ec2 start-instances --instance-ids i-1234567890abcdef0

💡 Cost tip: stop instances you are not using — you are billed for running time. The Free Tier includes a small instance for 12 months.