The legend is an indispensable element of a map. This is what gives the keys to the links between the entities presented and the symbols used to realize the graphic view. Some symbols are conventional, others may seem intuitive - but beware of this simplicity. To be sure there is no misunderstanding in the comprehension, words must be used to characterize the graphic signs.
See also: Graphic Semiology, symbol
[French: Légende]