Clefs

A clef tells you which notes the lines and spaces on the staff represent.
It basically gives the staff its meaning.

Two clefs are normally used: the treble clef and the bass clef.

The treble clef circles one specific line on the staff.
That line is G, which is why we also call it the G clef.

The line between the two dots of the bass clef is the F line.
That’s why we also call the bass clef the F clef.