Or what about keyboard symbols, or even the real meaning behind these popular emojis? It’s easy to look over these things, ...

We’ll need a key to show what the symbols mean. I still need to show where the hills are. This where contours come in. Contours are lines drawn on maps that join places of the same height.

Symbols show important landmarks, places and areas. They are used because maps are usually too small to contain lots of writing A key is a guide which explains what the symbols on the map mean.