Original: Hanja-mal or hanja-eo refers to words which can be written with hanja, and hanmun refers to Classical Chinese writing, although "hanja" is sometimes used loosely to encompass these other concepts.
Simplified: Hanja-mal or hanja-eo is about words which can be written with hanja. Hanmun (í ë) is about the Chinese Classical writing, but hanja can sometimes be used to generally mean hanmun too.