How to see what opengl version i have?


Currently I am using c and opengl and have got to the point where I want to see the vast and fantastical world of opengl 2.0 and shaders. I did a test from a website

said I did not support it. Ran the program, linked everything and the text came up saying not supported.

I than tried glinfo and it said i was on 2.1.2. How do I know which is right? Or is the lighthouse one wrong? Thanks a lot