Trying to understand ledged lines in between staffs

1. How do we remember the lines on a staff?
2. What do you call the lines that fall between the staffs?
3. What does every line on the staff represent?

How do we remember the lines on a staff?

The notes in the spaces between the treble clef staff lines are easy to remember. They spell the word FACE, starting at the first space note, F, and heading up to the E in the top space on the staff. No need to learn any other mnemonic here — everybody just uses FACE.

What do you call the lines that fall between the staffs?

A ledger line or ledger line is used in Western musical notation to notate pitches above or below the lines and spaces of the regular musical staff. A line slightly longer than the note head is drawn parallel to the staff, above or below, spaced at the same distance as the lines within the staff.

What does every line on the staff represent?

The modern staff comprises five lines and four spaces. The modern stave comprises five lines and four spaces. Every line or space on the staff represents a white key on the keyboard. Every line or space on the stave represents a white key on the keyboard.