Kanji
Most kanji characters can be pronounced at least two different ways according to whether the word is a native Japanese word (this is called the “kun” reading, or “kun-yomi”), or whether it came from Chinese (this called the “on” reading or “on-yomi”). Kanji that stand alone usually have kun-yomi, while kanji compound words usually have on-yomi. For example, 山 on its own is "yama" (the Japanese word for “mountain”). When it is combined with another word or name, it is pronounced  "san" e.g. “Fuji-san” (Mount Fuji).