If you know how to read music, you're already familiar with the bass clef, also known as the F clef. Similar to how the treble clef allows you to notate musical notes in the upper registers ...

Reading the stave/staff and understanding pitch. You can think of music notation as being a little bit like an X/Y graph; ...

There are many different mnemonics that can be used to remember the notes on the alto clef (reading from the bottom line up). You could use this mnemonic to remember the notes on the lines: You ...

Hence, a bass player would use the bass clef, as they play lower pitched notes, where a guitarist would use the treble clef.