What are shelves?
Shelves is the plural form of shelf. A shelf is a flat,
horizontal surface that holds objects or books. A shelf is
separated by usually 4 inches to 8 inches of empty space, with
another shelf above, and each shelf attached to sides to give the
'bookshelves' shape and stability. Many bookshelves also have a
backboard so nothing falls out from the back; some are enclosed on
the front with wood or glass. They are referred to as shelving unit
or bookshelves for use in the home, or just shelving for use in a
business or garage. Garages usually use metal or plastic; homes use
wood, plastic, or metal.