If you collect too much of everything to even use much of it, then you are a packrat. If you enjoy actually using the things that you collect in your area of interest, then you are a hobbyist. If you collect only to stick an inventory number on it and set it in a vacuum-sealed display case with a nice little placard in front stating its origin and value, then you are a serious collector.
Most people collect something.
Guns, clocks, beer steins, plates, coins, shoes, duck decoys, Beanie Babies, comics, old coffee pots. You name it and someone collects it. You hate it and someone will buy it off of you. Collecting used to be all legwork - traveling to auctions, flea markets, and garage sales hoping to find the piece that would fill out one s collection. Then a few years ago, a few online auction sites began to spring up, and made collecting a little easier by linking buyers with sellers.