No subject

A map coordinate system is either a geographic system
(like UTH or latitude/longitude) or an arbitraly coordinate system
used to reference the locations of objects in a two-dimensional
space. 
A map projection describes the manner in which the spherical
surface of the earth is represented on a two-dimensional surface.
It attempts to minimize distortionin area,shape,distance and
direction.
See also the reference
"Map Projections - A Working Manual " ,Snyder, 1989

And my private view.
Projections are used eg for UTH . For small area are not needed.
I'm a civil engineer and about map projections I learned
50 years ago.
Now I get the projection from the sample problem.
Later the user from Geography Department will know what
projection to use.

                            BRGRDS Romek