How do locator maps work?

How do locator maps work? A Locator map is an item which can be used as a visual aid when exploring the Overworld or The End. It allows a player to capture surface features of areas they visit, plotting them on a hand-held map. It also allows players to locate other players, as the name states.

A Locator map is an item which can be used as a visual aid when exploring the Overworld or The End. It allows a player to capture surface features of areas they visit, plotting them on a hand-held map. It also allows players to locate other players, as the name states.