.NET Framework is a new and revolutionary platform created by Microsoft for developing applications. Microsoft release of the .NET Framework runs on the Windows operating system, it is fast becoming possible to find alternative versions that will work on others. The .NET Framework has no restriction on type of applications, allows the creation of Windows applications, Web applications, Web services, and pretty much anything else you can think of.
The .NET Framework has been designed so that it can be used from any language. All of this provides a hitherto unthinkable level of versatility and is part of what makes using the .NET Framework such an attractive prospect.