The .NET Framework is a platform that allows development of Windows applications, web applications, and web services using languages like C#, Visual Basic, and C++. It consists of common language runtime, framework class library, and components for tasks like data access, web development, web services, and windows applications. The common language runtime provides a common execution environment and handles tasks like memory management. The common type system and common language specification allow integration and interoperability across languages. The framework class library is a large collection of reusable classes for tasks like input/output, collections, security, and data access.