From Wikipedia:

In geometry, a coordinate system is a system which uses one or more numbers, or coordinates, to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space.

The following text briefly explains the coordinate systems being used in astronomy, some of which are listed below:

RA / DEC

RA (right ascension) and DEC (declination) are the longitudes and latitudes of the sky. RA corresponds to east / west direction, similar to longitude, while DEC measures north / south directions, like latitude.

WCS

World Coordinate System (WCS) is a set of transformations that map pixel locations in an image to their real-world units, such as their position on the sky sphere. These transformations can …