The stave is made up of five lines and four spaces. The lines and spaces have no meaning until a clef is placed at the beginning of the stave.
These notes have no meaning as the stave has to be defined by placing a clef at the beginning.
Now the treble clef has been included we are able to name the notes below.
D E F G A B C D E F G
Similarly if the bass clef is used we can also name the notes.
F G A B C D E F G A B