Light year is a measure of

Light year is a measure of

time
distance
total amount of light falling on the Earth in a year
average intensity of light falling on the Earth in a year
This question was previously asked in
UPSC NDA-2 – 2017
A light-year is defined as the distance that light travels in vacuum in one Julian year (365.25 days). Because light travels at a finite, constant speed in vacuum, the distance it covers over a fixed period of time is a specific value. Therefore, a light-year is a unit used to measure distances, particularly in astronomy, for vast interstellar and intergalactic scales.
– A light-year is the distance light travels in one year.
– It is a unit of distance.
– Used for measuring large distances in astronomy.
The speed of light in vacuum is approximately 299,792,458 meters per second. One light-year is approximately 9.461 trillion kilometers (9.461 × 10¹² km) or 5.879 trillion miles (5.879 × 10¹² miles). Other units of astronomical distance include the astronomical unit (AU) and the parsec (pc).