Hell is oneself, Hell is alone, the other figures in it merely projections.
While most maps, paper or computer, are flat, the world isn’t. Map projections are mathematical methods for representing part or all of the quasi-spherical Earth (irregular oblate spheroid, to be more precise) on a flat surface. The book Flattening the Earth: Two Thousand Years of Map Projections, covers the history and many of the hundreds of projections devised to “flatten the earth”. [...]
Just as a map projection viewer alone, Flex Projector (Java; versions for Windows, Linux and Mac) would be worth a look. It has over 25 pre-defined map projections that you display (along with listed values for their areal/scale/angular errors), and includes the ability to display two projections at once for comparison purposes. [...]