Scripting and Coding Dictionary

I want to know this because Im making a physics sandbox game and Im just making sure that im ok with C# scripting. so can someone help me out here and make a small list of different stuff like for example:

Vector3 = (Meaning) or if = (Meaning)

sorry im quite new to C# coding but thanks for helping

If you it would help allot if you could post different functions or small samples of codes that do different things and if your very kind and helpful maybe point out what it does and what it means