As globes are the only true way to represent the surface of the earth while maintaining accurate relationships of distance and location, the projection becomes difficult on a 2d flat surface. No 2d map can accturaely preserve a particular quality and thus maps cater to the particular user. World maps incorporate such a large area, they are required to compromise between accurancy and a representable visibility.

The most popular and widely used projection, the Mercator Projection, creates a large amount of distortion. You can see from the map that Greenland is nearly 3x its actual size. North America appears to be 2x the size of Africa when it's barely 2/3 the size.