AMI and Instance Concepts

This section describes AMIs and instances, the basic building blocks of Amazon EC2. Before accomplishing anything with Amazon EC2, you must understand the concepts in this section.

An Amazon Machine Image (AMI) is an encrypted machine image that contains all information necessary to boot instances of your software. For example, an AMI might contain all the software to act as a web server (e.g., Linux, Apache, and your web site) or it might contain all the software to act as a Hadoop node (e.g., Linux, Hadoop, and a custom application).

You launch one or more instances of an AMI. An instance might be one web server within a web server cluster or one Hadoop node.