What are the main features of the mercator projection?

Mercator:

Mercator projection works very poorly in polar regions and becomes undefined at the north and south poles. Historically Mercator is interesting because it is one of the oldest map projections to be used. Christopher Columbus used the Mercator projection in his travels to the new world. This projection is often used in navigation because any straight line is a rhumb line (a line of constant direction). Parallels of latitude and longitude are straight. Features increase in size as the map approaches the poles. Areas and shapes of large areas are distorted. Distortion increases away from the equator and is extreme in polar regions. However, being a conformal projection, angles and shapes within any small area are essentially true.