Units of distance as commonly used in astronomy etc.
From shortest to longest:
1 astonomical unit (abbreviated: au or AU) = approximately 150 million kilometers, or 93 million miles.
1 light year (abbreviated: ly) = 63241.077 astronomical units. Approximately 9.46 trillion kilometers, or 5.88 trillion miles.
1 parsec (abbreviated: pc) = 3.26 light years and 206265 astronimical units. Approximately 31 trillion kilometers, or 19 trillion miles.
1 kiloparsec (abbreviated: kpc) = 1 thousand parsecs. Approximately 3262 light years.
1 megaparsec (abbreviated: Mpc) = 1 million parsecs. Approximately 3.26 million light years.
1 gigaparsec (abbreviated: Gpc) = 1 billion parsecs. Approximately 3.26 billion light years.