Parsec
Symbol: pc
Parsec is the shortcut of "parallax of one arcsecond".
It is defined as the length of the adjacent side of an imaginary right triangle in space. The two dimensions that specify this triangle are the parallax angle (defined as 1 arcsecond) and the opposite side (which is defined as 1 astronomical unit (AU), the distance from the Earth to the Sun). Given these two measurements, along with the rules of trigonometry, the length of the adjacent side (the parsec) can be found.
1 parsec equates to
30.856776 * 1015m
=30,856,776,000,000,000m
1m = 0.000000000000000032407793pc