The .NET Framework provides a common platform and language runtime for multiple programming languages. It includes the Common Language Specification (CLS), which defines interoperability standards, and the Common Language Runtime (CLR), which handles memory management, security, and code execution. The .NET Framework also includes a large class library called the Framework Class Library (FCL) that contains types and methods for building applications. Developers can use Visual Studio to create .NET applications using languages like C# and VB.NET, which compile to Microsoft Intermediate Language (MSIL) code that is executed within the CLR.