Forgive my ignorance. What's the difference between a smart phone and a multimedia phone?

A smartphone is a phone that also incorporates the functions of a PDA, and it usually has a good camera. There is no such thing as a specifically named phone as "multimedia" phone. Multimedia on devices are all about music, video playback, games, image viewing, and web browsing. There is no definite definition of a multimedia phone, but I believe that all smartphones are multimedia phones.