The Bass Clef

The Bass Clef also known as the F Clef is generally used for
the lower voices in music for vocalists and instrumentalists.
(It's the usual bottom line in piano pieces.)

It's called the F Clef because of its focus on the F. (It's the line
in between the dots.)

Clefs are focused on a note to give the reader a point of
reference. Without this reference, we'd have no concrete way
to know where or what the notes are.