Jacob Eiting on OpenGL and the GPU:
For many programmers the GPU is a part of the system shrouded in mystery. A realm best left to heavyset bearded types who toil away in the deep recesses of the gaming industry. With all the abstraction on top of the GPU, all but a few programmers can live out their daily lives without so much as a thought about how the things they make are actually rendered. Living behind these abstractions is fine, until you reach a limit, usually one of performance. When reaching these limits it can be really helpful to have a basic understanding of the GPU.
Maybe the best and most concise intro I’ve heard to understanding the terms that get thrown around when talking about graphics programming, and why you might want to know more about it.