How does a bass clef determine the pitches on a staff?

In musical notation, a clef is a symbol placed at the beginning of a staff to establish a reference point for pitch.

The bass clef, also known as the F clef, determines the pitches on a staff by fixing the position of the F below middle C. In modern notation, this F is specifically assigned to the second line from the top of the staff. By anchoring this specific note, the clef provides a "key" that allows musicians to identify the pitch of all other notes written on the staff lines and spaces.1

While modern usage consistently places this F on the fourth line from the bottom (the second line from the top), historical variations such as the baritone clef previously set F at the middle line of the staff.12