The amount of time it takes for the light from that certain galaxy to reach the Earth. The average speed of light (light speed) is 299 792 458 m/s. So it would take about 5000 years for the light from that certain galaxy to reach Earth. So doing simple math (299792458 x 5000) that certain galaxy is about 1,498,962,290,000 miles away from the Earth. Sorry for going on a bit of a rant I just got out of hand. I hope this helped in some way.
