The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion (3.1×1013) kilometres (about 19 trillion miles).
In Exorace, 1 parsec is the distance of 1 square (horizontal or vertical) in the star map. The distance between 2 stars is calculated using the euclidean distance according to their position in the map.