A map projection is a way of showing the three dimensional Earth's surface on a paper map so that it least distorts or changes the shape, area, distance, and direction of features on a globe. Projections are done by casting shadows of the globe on paper.

 

The attempt to make a round globe fit onto a completely flat surface is not easy. Map projections try to correctly show shape, area, distance and direction on a flat surface. However to preserve some characteristics correctly, some others have to be altered. This is called distortion. Different types of projections are used to present different characteristics of the Earth.