C# is a language. As the name implies, .NET is a "Framework" that provides a library of support for different coding languages. You can use Visual Basic under .NET also for example.
C# is one of the powerful OOPs language which is built on the .NET framework. Both are used to develop custom software and applications for SMBs. For custom .NET and C# programming solutions, contact Chetu. To know more, visit: WWW.CHETU.COM