There are many ways of making maps. Since a map is a 2-dimensional representation of a curved surface (a globe), the map cannot be perfectly accurate. These map-making methods are called projections because cartographers have to project a 3-D surface onto a 2-D map. There are many different types of projections that have different uses. Some projections preserve compass directions but distort areas (like Mercator projections), while others preserve area but distort distances and compass directions (like Robinson projections).