OpenGL (Open Graphics Library) is a standard specification defining a cross-language cross-platform API (application programming interface) for writing applications that produce 3D computer graphics (and 2D computer graphics as well). The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL was developed by Silicon Graphics and is popular in the computer and video games industry where it competes with Direct3D on Microsoft Windows platforms. OpenGL is widely used in CAD (computer-aided design), virtual reality, scientific visualization, information visualization, flight simulations and video game development.
Uses in SketchUp
SketchUp can do the necessary calculations to represent a 3D space on the 2D surface of a monitor by itself, but it drastically slows down the application. Most modern computers and graphics cards present hardware support for such operations.
- en.wikipedia.org - Wikipedia article on Open GL