Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides secure, resizable computing capacity on a Cloud. It is designed to make web-scale Cloud computing easier for developers.
Amazon EC2's simple web service interface allows you to obtain and configure capacity with ease. It provides you with complete control of your computing resources and let's you use Amazon's computing environment. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity (both up and down), as your computing requirements change. Amazon EC2 allows you to save computing costs as you pay only for capacity that you actually use. Amazon EC2 provides developers with the tools to build failure-resilient applications and to isolate them from common failure scenarios.