Many times I have seen that people asking about added new features in different C# versions like C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0 & C# 6.0. So to know about C# different version wise new features please once go through below link. Here you will get also C# basic history & programming concepts:
https://en.wikipedia.org/wiki/C_Sharp_(programming_language)