Hanja is the Korean word for Chinese characters. It is about the Chinese characters that are borrowed from the Chinese language and used in the Korean language with Korean pronunciation. "Hanja-mal" or "hanja-eo" is about words which can be written with hanja. "Hanmun" (한문) is about the Chinese Classical writing, but "hanja" can sometimes be used to generally mean "hanmun" too. Hanja was never very greatly changed, so almost all of the Chinese characters in hanja are exactly the same as in traditional Chinese, except maybe the stroke order for a few words. Only a few hanja characters are unique to Korea.