What is a parsec and how is it measured? Astronomical units of measurement are mostly pretty straight-forward:


Astronomical Units refer to the mean Earth-Sun distance (~150 million km or 93 million miles)
Light years are the distance light travels in a year (~9.46 × 10^12 km)


Another astronomical unit of measurement is the parsec.  What is a parsec and how is it measured?
A parsec is approximately 3.26 times a light year or 206,265 Astronomical Units (AU).

According to "Cosmic Reference Guide" (Caltech), the word 'parsec' stands for "parallax of one arc second", and is (according to the website):


  the length of the long leg of a right triangle, whose short leg is one astronomical unit when the angle between the Sun and the Earth, as seen from an object in space (a star for example), is one arcsecond


Illustrated (from the link above):