“A sham is a decorative pillow that matches the comforter and is made with the same material, color, and print,” says Sun. “These typically come in normal bed pillow sizes (standard for twin, full, queen, or king) that correlate with the comforter size." Shams typically serve a decorative purpose, as they are placed in front of sleeping pillows and look nicer compared to regular pillow cases. However, Sun says they are also functional since their placement protects the sheets and pillows from dust and dander during the day.