OpenGL is a cross-language, cross-platform API for 2D and 3D computer graphics. It was developed by SGI in 1992 and is widely used for CAD, VR, and games. OpenGL ES is a subset of OpenGL designed for embedded devices like phones and provides functions like glVertexPointer and glDrawElements to facilitate drawing. Key OpenGL concepts include the camera model using functions like gluLookAt, glFrustum, and glViewport to control the viewing volume and screen projection.