ㄴ답니다

Gently telling an audience something

A squashed form of 다고 합니다, literally they say that. In practice it is how an explainer or narrator hands the audience a fact, as in the lines teaching that a single portion is called 인분 or that the huge mushroom is called an emperor mushroom. It is polite and slightly storybook, warmer and less official than plain 습니다, and it also works for relaying what people generally say. After a noun the shape becomes 랍니다 instead.

Register: polite; explainer and narration voice