A light-year is a unit of distance, not time. It's the distance light travels in one year.

Here's a breakdown:

* Light travels at approximately 299,792,458 meters per second.

* There are 31,536,000 seconds in one year.

Therefore, one light-year is roughly:

* 9.461 trillion kilometers (9,461,000,000,000 km)

* 5.878 trillion miles (5,878,000,000,000 mi)

It's an incredibly vast distance!