AWS AMI

AMI is an acronym for Amazon Machine Image and represents an EC2 instance which has been customised (Think of an AMI as a template).

There are three ways to instantiate an EC2 instance from an AMI:

From the library of available Amazon AMI images; an example is when we create a new t2 micro image via the AWS management console
From a library of commercially available AMI images via the AWM Marketplace AMI
By creating your own AMI template based on your own software, configuration

Note that AMI are built for a specific region and the use case is when you wish to have faster EC2 configuration and start times as the software is already pre-installed on the EC2 image

The process for creating an AMI is as follows:

Create a base EC2 instance and then customise the instance with the required configuration and software
Stop the instance to ensure data integrity (i.e. Nothing is being written to the instance whilst an AMI is being created from it)
Create the AMI; doing so will also create the necessary EBS volume snapshots

The AMI is now complete and available for other EC2 instances to be launched from it