A light year is a unit of distance that is used to measure astronomical distances. It is defined as the distance that light travels in a vacuum in one year, which is approximately 5.88 trillion miles (9.46 trillion kilometers or 9.4607×1015 m ).
The light year is a very large unit of distance, and it is used to measure distances between celestial objects that are too vast to be expressed in smaller units. For example, the distance from the Earth to the Sun is about 93 million miles, which is about 0.0016 light years. The distance from the Earth to the nearest star, Proxima Centauri, is about 4.22 light years.
Because the light year is such a large unit of distance, it is often used to express distances between objects in the universe, such as stars and galaxies. It is also used to measure the speed of light, which is the fastest speed at which anything can travel and is equal to about 186,282 miles per second (299,792 kilometers per second).