Web Services

Web services are typically application programming interfaces (API) or web APIs that can be accessed over a network, such as the Internet, and executed on a remote system hosting the requested services clients and servers that communicate over the Hypertext Transfer Protocol (HTTP) protocol used on the web. Such services tend to fall into one of two camps: Big Web Services and RESTful Web Services.

Source: Wikipedia
http://en.wikipedia.org/wiki/Web_service

ASP.NET

ASP.NET is a web application framework developed and marketed by Microsoft to allow programmers to build dynamic web sites, web applications and web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages (ASP) technology. ASP.NET is built on the Common Language Runtime (CLR), allowing programmers to write ASP.NET code using any supported .NET language.

Source: Wikipedia
http://en.wikipedia.org/wiki/ASP.NET

.NET

The Microsoft .NET Framework is a software framework that can be installed on computers running Microsoft Windows operating systems. It includes a large library of coded solutions to common programming problems and a virtual machine that manages the execution of programs written specifically for the framework. The .NET Framework is a Microsoft offering and is intended to be used by most new applications created for the Windows platform.

The framework's Base Class Library provides a large range of features including user interface, data and data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. The class library is used by programmers, who combine it with their own code to produce applications.

Programs written for the .NET Framework execute in a software environment that manages the program's runtime requirements. Also part of the .NET Framework, this runtime environment is known as the Common Language Runtime (CLR). The CLR provides the appearance of an application virtual machine so that programmers need not consider the capabilities of the specific CPU that will execute the program. The CLR also provides other important services such as security, memory management, and exception handling. The class library and the CLR together constitute the .NET Framework.

Version 3.0 of the .NET Framework is included with Windows Server 2008 and Windows Vista. The current version of the framework can also be installed on Windows XP and the Windows Server 2003 family of operating systems. A reduced version of the .NET Framework, the .NET Compact Framework, is also available on Windows Mobile platforms, including smartphones. Version 4.0 of the framework was released as a public Beta on May 20, 2009.

Source: Wikipedia
http://en.wikipedia.org/wiki/.NET_Framework

Microsoft Silverlight

Microsoft Silverlight is a web application framework, integrating multimedia, graphics, animations and interactivity into a single runtime environment. Initially released as a video streaming plugin, later versions brought additional interactivity features and support for .NET languages and development tools. The current version, 3.0, was released on July 9, 2009.

It is compatible with multiple web browser products used on Microsoft Windows and Mac OS X operating systems. Mobile devices, starting with Windows Mobile 6 and Symbian (Series 60) phones, will likely become supported in 2010. A free software implementation named Moonlight, developed by Novell in cooperation with Microsoft, is available to bring compatible functionality to Linux, FreeBSD and other open source platforms.

Source: Wikipedia
http://en.wikipedia.org/wiki/Microsoft_Silverlight