What is the difference between a crock pot and a slow cooker?

Crock-Pot was the original slow cooker, but it's just a genericized brand name (as mentioned, like Kleenex or Xerox). Technically, if it's not made by Rival, it's not a Crock-Pot, it's a slow cooker.

Crock Pot is just a particular brand name for one line of slow cookers. Just like Kleenex is one brand of facial tissue, or Clorox to mean bleach, Windex.....

Crockpot is a brand name of a slow cooker. They're the same thing.