The bass clef is a musical symbol used to notate lower-pitched sounds, typically assigned to instruments like the cello, bassoon, and double bass, as well as the left hand of the piano. It indicates that the notes on the staff represent pitches lower than those represented in the treble clef, with the F line marking the fourth line of the staff. Understanding the bass clef is crucial for reading and writing music accurately, especially when analyzing harmonic structures and voice leading.