.NET Framework is a Microsoft-developed software framework primarily for Windows that includes a comprehensive class library and supports language interoperability across multiple programming languages. It operates in a managed environment provided by the Common Language Runtime (CLR) and features components such as ADO.NET for data access, ASP.NET for web applications, and various programming paradigms including object-oriented and functional programming. The document outlines detailed topics like data types, exception handling, state management, and advanced technologies such as WCF and MVC used in .NET development.