What does a beat signify in musical notation?

A beat in musical notation signifies a unit of time in music. It is the basic unit of musical rhythm, and it determines how fast or slow a piece of music is played. Beats are usually represented by vertical lines, or "bar lines," on the staff, and they are grouped together into measures, or "bars." The number of beats in a measure is determined by the time signature, which is located at the beginning of a piece of music. Common time signatures include 4/4 (four beats per measure), 3/4 (three beats per measure), and 2/2 (two beats per measure).