OpenGL (Open Graphics Library) is a cross-platform, hardware-accelerated, language-independent, industrial standard API for producing 3D (including 2D) graphics. It is a software interface to graphics hardware, and modern computers have dedicated GPU (Graphics Processing Unit) with its own memory to speed up graphics rendering. OpenGL provides a set of functions that can be called by the client program to render 2D and 3D vector graphics. It is designed to be implemented mostly or entirely in hardware, although it is possible for the API to be implemented entirely in software.

Some key features of OpenGL include:

• OpenGL Utility Library (GLU): built on-top of the core OpenGL to provide important utilities (such as setting camera view and projection) and more building models (such as qradric surfaces and polygon tessellation) .
• OpenGL Utilities Toolkit (GLUT): needed to interact with the Operating System (such as creating a window, handling key and mouse inputs); it also provides more building models (such as sphere and torus) .
• OpenGL Extension Wrangler Library (GLEW): a cross-platform open-source C/C++ extension loading library that provides efficient run-time mechanisms for determining which OpenGL extensions are supported on the target platform.

OpenGL is widely used in computer-aided design (CAD), virtual reality, scientific visualization, information visualization, flight simulation, and video games. It is a good way to begin learning computer graphics, and there are many resources available online to help beginners get started.