paypal question

I am sorry, I know that for some of youse people this is a stupid question,
how does paypal work, I'm looking to buy some stuff on ebay from people
(mostly
small merchants I think) who want the buyer to use paypal.  I have never used
ebay before and I know that some of you must use it a lot.  If you want to
contact me off line that is ok, so I don't waste the bandwidth and stuff.  Not
to mention cluttering up the list,  Thanks in advance
JP

John Poynton
79 Midget, Yellow Fever
Havertown, PA