@Carmen816,
The word cappelletti means “little hats” which is what this pasta should resemble; they're round, from Modena, stuffed with meat, and traditionally served in broth.
Ravioli are claimed to come from either Genoa or Cremona, depending on who you believe, and are square in shape and are traditionally stuffed with beef or cheese.
Pictures:
1. Cappelletti
2. Ravioli