What purpose do legends serve on maps?

Legends on maps are crucial because they explain the symbols and markings used throughout the map. They provide the viewer with a key to understanding what various icons, colors, and lines represent. For instance, a legend may indicate that a certain symbol denotes a river, while a different one might indicate a park or an urban area. This understanding is essential for effectively interpreting the geographical information presented on the map, allowing users to glean insights about the physical layout, features, and elements depicted.

While legends do clarify symbols, the other options serve different specific functions on maps. Indicating political boundaries relates more to line markings rather than the legend itself, showing temperature variations typically requires a different kind of map or graphic presentation, and depicting resource distributions is usually represented by thematic maps with specific data visualization, rather than being the primary function of a legend.