A yard is a unit of length in the imperial and US customary systems, equal to 3 feet or 36 inches.

A light-year is a unit of astronomical distance, representing the distance that light travels in one year in a vacuum.

This is because a light-year represents an astronomically vast distance, while a yard is a very small, everyday measurement.

This specific conversion isn't typically used directly in practical scenarios due to the extreme difference in scale, but it serves to illustrate the immense vastness of space.