The Azure Services Platform (Azure for short) encompasses the new Windows Azure cloud services operating system and various services.  Commercial availability is is H2 2009.

It’s all quite well explained on the Azure website.

It includes Windows Azure which is a virtualised appearance of a computing and storage platform including clever scalability and availability management.  It can run .NET based applications and native code (later).  You can leverage all your ASP.NET skills.  There are Visual Studio CTP tools available that include a local test environment.  A web and webservice interface allows you to control your computing and storage instance needs.

This of this as pay for time Windows Server (but not quite) and storage services.  See the Channel9 video for the inside whiteboard discussion.

It also encompasses other (separately usable/available to varying degrees) platform cloud services (as shown on the website) that provide additional functionality:

• Live Services (Channel9 video);
• .NET Services (Channel9 video) for connecting on-premise and cloud systems together , doing federated identity and Windows Workflow in the cloud;
• SQL Services (formerly SSDS, Channel9 video);
• SharePoint Services;
• Dynamics CRM Services.

Those may also be charged for by various measures.

On top of that, you can also use Windows Live, Office Live, Exchange Online, SharePoint Online and Dynamic CRM Online.

You’d be right in thinking that Amazon EC2 + S3 or GoGrid already provide virtualised server and/or storage in beta or released products in some cases.