It is not possible to map from a curved surface
like a sphere or ellipsoid to a plane without distortion.
There are different possibilities for describing
the properties and characteristics of map projections.
mathematical or geometrical properties:
(e.g. shape and aspect of the mapping surface)
(e.g. distortion behaviour as conformity, equal area
condition, equidistant lines ...)
map projection methods for specific purposes (e.g. area of
usage (dimension, position on the earth, shape of
the optimized map projection parameters covering the needs