What's the difference between 魔{ま} and 鬼{おに}?


Both seem to mean "demon". Are they synonyms?




悪魔【あくま】 is the word which corresponds to the English word _demon_. For example
[Belphegor](https://en.wikipedia.org/wiki/Belphegor) is a typical 悪魔.

魔 by itself sometimes refers to 悪魔, but it's a more general kanji which means
_evil_ or _evil things_. It includes Western-style 悪魔, Japanese evil entities
like [閻魔](https://en.wikipedia.org/wiki/Yama), and monsters in general.

In modern usage, 鬼 usually refers to one certain type of Japanese monster,
which has two horns and colorful (mainly red) skin. Here's the result of
Google Image Search:

[![Oni](https://i.stack.imgur.com/SiwVT.png)](https://i.stack.imgur.com/SiwVT.png)

The kanji 鬼 probably used to refer to ghosts and demons in general (Wikipedia
says 鬼 means _ghost_ in Chinese), and serious Buddhists may have another
definition I'm not familiar with. But it's safe to think it only refers to
this stereotyped 鬼 today, at least among ordinary people.

