Portal:OpenGL Concepts/Intro

OpenGL is a OpenGL Specification, a document that describes the behavior of a rasterization-based rendering system. It defines the API through which a client application can control this system. The OpenGL rendering system is carefully specified to make hardware implementations allowable.

Hardware vendors, the people who make GPUs, are responsible for writing implementations of the OpenGL rendering system. Their implementations, commonly called "drivers", translate OpenGL API commands into GPU commands. If a particular piece of hardware is unable to implement all of the OpenGL specification via hardware, the hardware vendor must still provide this functionality, typically via a software-based implementation of the features missing from hardware.

The OpenGL specification is governed by the OpenGL ARB, which is a member of the Khronos Group. They develop new versions of the specification and decide how to expose various hardware features through OpenGL. Major hardware vendors, such as NVIDIA, AMD, and Intel, are members of the ARB.