What is the purpose of a door hole filler plate and how can it be used to cover up unwanted holes in a door?

A door hole filler plate is used to cover up unwanted holes in a door, such as those left behind by removed locks or handles. It serves the purpose of providing a clean and finished look to the door. The filler plate is installed over the hole and secured in place, effectively concealing the opening and restoring the door's appearance.