What are the mouse interface and keyboard interface of desktop computer?

Desktop computers have two mouse interfaces, namely:

PS/2 interface (often called "round mouth", basically discontinued at present, the old mouse used this interface many years ago);

USB interface (usually called "flat mouth", now most mice are this interface).

Desktop computers have two keyboard interfaces, namely:

PS/2 interface (usually called "round mouth", this interface is relatively rare, but some models of keyboards still use this interface);

USB interface (usually referred to as "flat mouth", now the keyboard is mostly this interface).

PS/2 interface diagram:

USB interface diagram: