What's an F Stop?

Ok Folks... when I said I was beginner I wasn't lying. I'm reading all about what is takes to make a create photo and I'm being bombarded by phrases such as F Stop, Aparture, Shutter Speed, ISO. What do these mean? Heck if I know! I'm working on finding out. Today I'm trying to tackle the question, "What is F stop?"

I stole this excerpt, written nicely in every jargon from Matthew Cole's homepage.

"My favorite analogy for exposure is filling a bucket of water. A bucket is of fixed size and needs a certain amount of water to fill it, just like film, which is of a set film speed and needs a certain amount of light to capture an image. To fill your bucket, you can pour a small stream of water for a long time or a fast stream of water for a short time. Either way, you end up with the same amount of water. In photography, the size of the stream of the water is analogous to the f/stop, the length of time you pour is analogous to the shutter speed, and the size of the bucket is analogous to the film speed. Broadly speaking, from the bucket's point of view, it doesn't matter which combination of stream size and length of time you choose as long as the right amount of water ends up coming in. Film is the same; within limits, it is indifferent to the combination of time and amount of light as long as the right amount of light eventually arrives"

He goes on to explain the technical aspect of F stop also.