.NET is essentially a system application that runs on Windows. The heart of .NET is the .NET Framework. The most important component of the framework is the CLR as the heart and soul of the .NET architecture. Every application written using the Framework depends on the CLR. Among other things, the CLR provides a common set of data types, acting as a foundation for C#, VB, and all other languages that target the .NET Framework. Because this foundation is the same no matter which language they choose, developers see a more consistent environment.