is an internet-scale cloud service platform hosted in Microsoft data center

a platform which provides operating system, a set of developer services that can be used individually or together.

a platform for running Windows applications and storing their data in the cloud.

a platform where all services (.NET Services, SQL Server, Live Services) installed which can be used by the applications

a platform where the code and/or data live in the cloud (internet), where somebody manages the system to use it

provides flexibility to run the application, store the data in the cloud or inside premise or both

there is a plan that Azure 2009 support unmanaged code as well i.e., the application are not built on .NET framework….. Its a great news.

no buying, installing, operating cost (hosted on the cloud, and maintained by someone else)

pay just for the computing and storage use rather then maintaining a large set of servers

can control the behavior of the application in the cloud by changing the information in the config file

can create, configure, monitor application using a browser-accessible portal using Windows Live ID

provides capability to use/integrate existing on-promises web applications

provides multiple internet protocols HTTP, REST, SOAP, and XML.

provides ready for consumption such as Windows Live, Microsoft Dynamics, Microsoft Exahange Online, SharePoint Online etc.

no buying, installing, operating cost

eliminates the need for planning, purchasing, and provisioning expensive hardware

manages critical operating system updates and management tasks, and letting to focus on the user needs

Turns capital expenses into operating expense

a pay-as-you-go pricing model, which provides high availability and dynamic scaling to match the usage of needs

For actual cost of Azure – pls visit Pricing & Licensing site