What is the similarity between bass and treble clef?

The similarity between the bass and treble clef is that they both have five lines and four spaces, and the notes are named the same on both clefs. However, the middle line of the bass clef is called the F line, while the middle line of the treble clef is called the C line. This means that the notes on the bass clef are written an octave lower than the notes on the treble clef.