OpenGL

OpenGL (Open Graphics Library) is a programming interface for 3D graphics which helps computer programmers make their 3D graphics perform better and faster by running parts of their programs on a video card (GPU) rather than just the central processor (CPU). Programming interfaces like OpenGL are usually called an "API," which stands for "Application Programming Interface".

OpenGL

Original author(s)	Silicon Graphics
Developer(s)	Khronos Group (formerly ARB)
Initial release	June 30, 1992; 32 years ago (1992-06-30)
Stable release	4.6 / July 31, 2017; 7 years ago (2017-07-31)
Written in	C[1]
Type	3D graphics API
Website	opengl.org

OpenGL is often compared to Direct3D, an API for 3D graphics on Windows. Programming for Direct3D is different in some ways because the APIs use different naming schemes for talking to a computer's graphics driver, which means that programmers need to write different code for OpenGL and Direct3D to do the same things.

OpenGL is owned by the Khronos Group. The Khronos Group writes the specification for OpenGL which describes how the API should interact with the GPU. It is then up to the manufacturers of GPUs to write code which matches this specification. Despite what the name suggests, OpenGL is not open-source.