.NET Framework is a software development platform created by Microsoft, released in 2000, that supports various programming languages and provides extensive class libraries for building web, desktop, and mobile applications. Key components include the Common Language Runtime (CLR), which executes applications, and the Framework Class Library (FCL), which offers reusable code, along with technologies like ASP.NET and ADO.NET for web development and data access. The framework ensures features such as memory management, language interoperability, version compatibility, and supports the development of service-oriented applications through Windows Communication Foundation (WCF) and Windows Presentation Foundation (WPF).