ELI5: Explain Like I'm 5

Room number

A room number is like an address. It's a way to identify a specific room in a building. For example, your bedroom at home might have the room number "5" on the door. That means that's the fifth room in your house. If you go to a hotel, every room will have its own room number so you can easily find it. Room numbers help people find where they need to go.