This list/table provides an overview of significant map projections, including those described by articles in Wikipedia. It is sortable by the main fields. Inclusion in the table is subjective, as there is no definitive list of map projections.
https://en.wikipedia.org/wiki/List_of_map_projections
1 Equal Area: Areas are conserved. 2  Compromise: Neither conformal nor equal-area, but a balance intended to reduce overall distortion. 3  Equidistant: All distances from one (or two) points are correct. 4  Other equidistant properties are mentioned in the notes.
https://en.wikipedia.org/wiki/List_of_map_projections
1 Conformal: Preserves angles locally, implying that locally shapes are not distorted. 2  Equal Area: Areas are conserved. 3  Compromise: Neither conformal nor equal-area, but a balance intended to reduce overall distortion.
https://en.wikipedia.org/wiki/List_of_map_projections
Mercator. Used for navigation or maps of equatorial regions. Any straight line on the map is a rhumb line (line of constant direction). Directions along a rhumb line are true between any two points on map, but a rhumb line is usually not the shortest distance between points.
http://egsc.usgs.gov/isb//pubs/MapProjections/projections.html
The UTM Grid. The best known use of the transverse Mercator projection is the specialized form called Universal Transverse Mercator (UTM) projection system. The UTM defines a grid covering the world between parallels 84°N and 80°S. The grid is divided in sixty narrow zones, each centered on a meridian.
http://progonos.com/furuti/MapProj/Normal/ProjNav/projNav.html
Map projection —A map projection is a systematic representation of a round body such as the Earth or a flat (plane) surface. Each map projection has specific properties that make it useful for specific purposes.
http://egsc.usgs.gov/isb//pubs/MapProjections/projections.html
1 Conic: In standard presentation, conic (or conical) projections map meridians as straight lines, and parallels as arcs of circles.
https://en.wikipedia.org/wiki/List_of_map_projections
For example, the basic Mercator projection is unique; it yields the only map on which a straight line drawn anywhere within its bounds shows a particular type of direction, but distances and areas are grossly distorted near the map's polar regions.
http://egsc.usgs.gov/isb//pubs/MapProjections/projections.html
Rhumb line —A rhumb line is a line on the surface of the Earth cutting all meridians at the same angle. A rhumb line shows true direction. Parallels and meridians, which also maintain constant true directions, may be considered special cases of the rhumb line. A rhumb line is a straight line on a Mercator projection.
http://egsc.usgs.gov/isb//pubs/MapProjections/projections.html
The type of projection and the properties preserved by the projection use the following categories: 1  Cylindrical: In standard presentation, these map regularly-spaced meridians to equally spaced vertical lines, and parallels to horizontal lines.
https://en.wikipedia.org/wiki/List_of_map_projections
what is the mercator projection used for
The best known use of the transverse Mercator projection is the specialized form called Universal Transverse Mercator projection system.  