Video cards and pipelines

[SagaLore]

I get the impression that a pipeline is just a stack or buffer, but there has to be more to it than that. Isn't some kind of out of sequence optimization done?

How would a video card perform without any pipelines? Or is the minimum at least 1 pipeline?

 

[biostud]

I thought a pipeline is where the pixels colors are rendered, adding textures and lightning and other effects.

 

[Regs]

This should help:

http://www.anandtech.com/video/showdoc.aspx?i=1821&p=3