Is C++ different with every program?

Question

I recently started getting into OpenGL(by recent I mean this moring) and I have been watching tutorials with it, but I have been noticing that C++ is a little different in OpenGL windows. I am learning C++ with Sololearn and a different Youtube tutorial(which was ALSO a little different) and this seeing these tutorials, it is almost COMPLETELY different! Like a new coding language! It is all confusing and I don't exactly get it.