Components of a virtual machine instance

A virtual machine instance running in EC2 is always created from an Amazon Machine Images (AMIs) and the process of the creation of an EC2 instance is referred to as a launch. Whenever we launch an instance we also need to define the amount of CPU, memory, and disk attached to the instance and we define those characteristics using an EC2 instance type.

Amazon Machine Images (AMIs)

An AMI provides all the software required to launch an instance including the following:

• The boot sectors and disk layout
• The operating system
• The cloud-init components to configure your instance at launch
• Default block device mappings that define the volumes to be attached to the instance
• Launch permissions...