Shader programming has been the largest revolution in graphics programming. OpenGL Shading Language (abbreviated: GLSL or GLslang), is a high-level shading language based on the syntax of the C programming language. With GLSL you can execute code on your GPU (aka graphics card). More sophisticated effects can be achieved with this technique. Therefore, knowing how OpenGL works and how each shader type interacts with each other, as well as how they are integrated into the system, is imperative for graphic programmers. This knowledge is crucial in order to be familiar with the mechanisms for rendering 3D objects. 'GLSL Essentials' is the only book on the market that teaches you about shaders from the very beginning. It shows you how graphics programming has evolved, in order to understand why you need each stage in the graphics rendering pipeline, and how to manage it in a simple but concise way.