Can someone explain PDF to me?

As you all know, I live in the sticks (ok, Tx brush country) and have a 26K connection -when SBC lets me.

I was adventurous enough to try opening this PDF file from Utterly Boring and, needless to say I gave up on opening it before tomorrow.

I *know* it stands for some kind of data file. WHY do people use it? I don't think I've heard of anyone who likes it (but I don't hang alot with computer geeks). All I know is that I dread clicking on a link with a PDF warning on it. I don't if I don't NEED to look. I shy away from video, too- same 26K reason.

Almost everyone has Word, or Apples' version that can be translated, why is PDF so used?