What is the difference between OpenGL and QtOpenGL?

Question

Qt

Just OpenGL or the OpenGL that comes with QtFramework ?
Do they differ in something other than the prefix in the names of classes, methods, functions and variables?
Is it worth spending time developing UI with OpenGL
when Qt widgets can be used for this?
Will the "slowness" of Qt widgets be noticeable compared to "homemade" ones?
Will Qt's OpenGL facilities be slower?
Maybe it's better to connect "pure" OpenGL?

Answer 1

Qt OpenGL is a module in Qt for building applications using OpenGL. In other words, this is the integration of OpenGL into the Qt framework.