What's the difference between UCE and spam?

Spam is a commonly used term for UCE. However, SPAM (often written in capital letters) is also the trademark of the Hormel company. On this site, we try to refrain from referring to UCE as spam, because the nice people at Hormel already have enough troubles defending their product's name. We do, however, use the term spammer to refer to any person degenerate enough to abuse the Internet system by sending UCE.