Definition of Parsec

A parsec is a unit of length used to measure large distances in space:

• 1 parsec is approximately 3.26 light-years or 3.086 × 10^13 kilometers
• It is defined as the distance at which one astronomical unit (AU) subtends an angle of one arcsecond
• Parsec is derived from 'parallax of one arcsecond'

This unit is commonly used in astronomy to express distances to stars and other far-off celestial objects.