The quote above showing info about pipelines is wrong, those are a different type of pipeline;
Pipelining in CPUS (what was linked to above) is usuall measured in stages, say a CPU has a 30 stage pipeline, then basically 30 operations can be in various stages of completion at one time, when an operation is being completed by the CPU it has to enter the first stage of the pipeline and as it progresses through every stage of the pipeline it gets a little more finished.
Ex: If a CPU wants to figure out (3+3+3)/2-1 then that enters the pipeline and at the first stage the CPU figures out 2-1, at the next stage the CPU figures out 3+3 and then the 6+3 and at the final stage it divides the 9/1. sorry for my poor example, the answer was 9 lmao.
The benefit of this type of pipelining is that say in my example above the CPU wants to figure out (3+3+3)/2-1 and after that wants to do 6x80, as soon as the first operation has passed the first stage of the pipeline, the second operation can enter the pipeline and begin being solved which means that there is a constant stream of operations being completed in a CPU at any given time.
Pipelines in a graphics card however refer to how many pixels can be drawn in one clock. Let us use my 7900GTX because I know everything to know about it
it has a clock speed of 750MHz which means that in 1 second 750,000,000 clocks are completed, and it has 24 pixel pipelines which means that in every one of those clocks, 24 pixels are drawn. So if we take 750 million x 24 we get the pixel fill rate of 18,000,000,000 pixels per second.
Hope I clarified things for ya a bit
EDIT/// Wow, im stupid. A stock 7900GTX has a 650MHz clock speed but whatever, I think you guys can figure it out.