Difference between もっとも and 一番 When expressing a superlative meaning ("the most ..."), what is the difference between the usage of and (e.g. vs. )

Simply, is colloquial/casual, and is formal/technical. Oh, this is one of the rare cases where words are more informal than the versions.

In addition, can only function as a modifier, while can work as a noun which means _number one_.

> * : OK
> * : NG
>