A light-year is the distance that light travels in a vacuum in one Julian year. It's a unit of astronomical distance.

Light travels incredibly fast, so the distance light covers in a year is immense. 10,000 kilometers is a very short distance compared to a light-year.

10,000 kilometers is a distance on Earth. In astronomical terms, it's extremely small, less than a millionth of a light-year.

This specific conversion is rarely used in daily life. It's primarily for astronomical contexts where vast distances are discussed.