According to the image given they represent what is called the Clefs. The image shows the treble clef and the bass cleft. And it exists the alto clef and the baritone clef. They are used to show or indicate the pitch of written notes. When they are on the stave, they serve to identify the name and the pitch of the notes.
Ok first of all, you should know the clefs bottom one is bass clef and top one is treble clef. so the lines are called a staff where you put the notes and everything.
