A map is an excellent way of communicating a lot of information. A map always has a purpose and the purpose determines what information is shown. A world traveler may need to know the climates in different countries; a rider to a city wants to find his way and see where hotels and places of interest are. A government official may need to know how land is being formed, and how much rainfall the land receives. Maps which shows one or two of such information are called thematic maps.