I am new to OpenGL extensions and shading languages. I am working on windows machine. Before starting up with a project, I would like to know what is difference between normal OpenGL, OpenGL extensions and OpenGL shading language? When these three can be used?
OpenGL is a graphics library, GLSL (the OpenGL shading language) is a part of OpenGL and used to write shaders. Extensions are additional, optional parts of the library. For modern OpenGL you will need OpenGL and GLSL.