The term "pillow sham" means a pillow with a "false front", stemming from the notion of "a trick". In the 1700's, specially made pillowcases were made to create decorative pillows with removable covers. These "false front" pillow covers became known as pillow shams!

A sham is a decorative pillow case that transforms normal sized pillow fills into useful accessories for one's bedding set. Pillow shams normally come in traditional pillow sizes: Standard Sham (26" x 20"), King Sham (36" x 20"), and Euro Sham (26" x 26"). Unlike the typical pillowcase, the pillow sham is often open in the middle of the back, with slightly overlapped fabric (or sometimes is closed with a hidden zipper). Pillow shams are usually sold in pairs made out of a fabric from a matching duvet cover.

Although they can definitely be slept on like normal pillowcases, pillow shams are usually used as support when sitting in bed and as decoration during the day. Sham pillows can be placed behind normal pillows when sleeping or just removed from the bed completely. Unlike throw pillows, cotton shams can be easily removed from their fills to be washed or replaced.