Notice the 4 and 2 chord then there is a line connected to the 0. I keep seeing tabs similar to this with a chord then a line connected to a single note like the 0. What is this saying to do exactly????

Notice the 4 and 2 chord then there is a line connected to the 0. I keep seeing tabs similar to this with a chord then a line connected to a single note like the 0. What is this saying to do exactly????
