A map legend is a table or chart included on a map to indicate the meaning of the map's varied symbols. This can be also be called the map's key.
Typical symbols included on a map legend are those that indicate cities, small towns, state capitals, county seats, railroads, mountain ranges, rivers, streams, dry lakes, boundaries and highways. On maps of buildings or compounds, the map legend may include symbols for buildings, doors, stairwells, windows, fences, property boundaries, shrubbery, water piping and electrical lines. The symbols used in a map legend vary widely depending on the type of map on which they are used.