The latest version of C# that came with Visual Studio 2012 and .NET Framework 4.5 is 5.0.  For those who are still working on .NET Framework 2.0, the version of C# you are using is 2.0.  Between these, you have 3.0 and 4.0.  So naturally you might ask what are the differences between these versions?  Don’t fear, help is here ;).  Fortunately, there are some information on the Internet that can provide you with these differences and in more detail than I can possibly explain here in my post.  Below are the links you can go to.  Enjoy!