Windows Azure provides a Microsoft application platform for the public cloud. You can use this platform to:
- Build a web application that runs and stores data in Microsoft datacenters.
- Store data for use with on-premises applications.
- Create virtual machines to develop, test, and run SharePoint and other applications.
- Build massively scalable applications for many users.
In short, Windows Azure offers a wide range of services that help you expand your IT capabilities without costly investments in your IT infrastructure.
See the video here