Amazon Elastic Compute Cloud is a part of Amazon.com's cloud-computing platform, Amazon Web Services (AWS), that allows users to rent virtual computers on which to run their own computer applications.
EC2 encourages scalable deployment of applications by providing a web service through which a user can boot an Amazon Machine Image (AMI) to configure a virtual machine, which Amazon calls an "instance", containing any software desired.
A user can create, launch, and terminate server-instances as needed, paying by the second for active servers – hence the term "elastic".
EC2 provides users with control over the geographical location of instances that allows for latency optimization and high levels of redundancy.
In November 2010, Amazon switched its own retail website platform to EC2 and AWS.
Generally, Amazon EC2 is priced on a per instance / per hour basis.
However, any instance can be rented on a per month basis as well.
In such case, Reserved and Spot Instances pricing can be applied, resulting in a significant discount.
Instances are priced depending on their "size", namely how much CPU and RAM are included.
Official website :- https://aws.amazon.com/ec2/