OpenGL Version 3.0 introduced a deprecation model, which allowed for the gradual removal of functions from the OpenGL specification. Functions or features can be marked as deprecated, meaning that they are expected to be removed from a future version of OpenGL. For example, immediate mode-rendering using glBegin/glEnd was marked as deprecated in version 3.0 and removed in version 3.1.
In order to maintain backwards compatibility, compatibility profiles were introduced with OpenGL 3.2. A programmer that is writing code for a particular version of OpenGL (with older features removed) would use the core profile. Those who wanted to maintain compatibility with older functionality could use the compatibility ...
