.NET is a framework and not a programming language. Hence we cannot compare .NET with other programming languages.

.NET framework has CLR (Common language runtime) which has the runtime libraries for all the languages supported by .NET. It is the responisbility of the runtime to take care of the code execution of the programs written using programming language.

.NET framework  performs responsibilities like  garbage collection (memory management), code access security,  code verification etc. In case of other programming languages these responsibilities has to be carried out by a programmer or s/w developer developing the application.

Advantage of using .NET is you can still continue programming in the language you are comfortable with.