Rests are used to indicate silence in music. There are different rests for different lengths of silence just as notes indicate different lengths of sound. The symbols below are very similar. The difference is that the half rest sits on top of the line, while the whole rest hangs below the line.The half rest indicates two beats of silence. The whole rest indicates four beats or a whole bar of silence. Small counting numbers are placed under rests.
It is important to keep counting and tapping your foot steadily on each beat regardless of whether a note or a rest appears in the notation. When you are playing with other musicians, someone else is likely to be playing while your part has a rest. When you play your next note, you need to be perfectly in time with them. This is difficult to do if you are not in the habit of counting.