An EC2 instance is a virtual server in the AWS Cloud.

An EC2 instance type refers to the hardware of the host computer used to power our virtual servers.

An EC2 instance consists of compute, memory, network, and storage.

Amazon EC2 provides several high level features, which include:

• Instances
• Machine Images
• Instance Types
• EBS Volumes
• Instance Store Volumes
• Key Pairs
• Security Groups

There are several services related to Amazon EC2 which can be used together:

• EC2 Auto Scaling
• AWS Backup
• Amazon CloudWatch
• Elastic Load Balancing
• Amazon GuardDuty
• EC2 Image Builder
• AWS Launch Wizard
• AWS Systems Manager

Terms:

Elasticity: The concept of acquiring resources when needed, and releasing resources when no longer needed. A resource or service must fulfil both scaling in and scaling out to meet the definition of the term.

Read the docs:

• AWS User Guide - What is Amazon EC2?
• AWS Well-Architected Framework Concepts - Elasticity