Cell phones vibrate using a small motor with a weighted disc that spins quickly. As the disc moves, it creates tiny shakes that you feel as a vibration. This helps you get alerts without sound. The Back Massager With Heat For Pain Relief, Back Massage Chair Pad, Chair Massager For Full Body Pursonic Chair Cushion With Heat and Vibration Vinsetto 6 Point Vibrating Massage Office Chair with Lumbar Heat Tip] Allow iPhone to Ring in Silent or Do Not Disturb Mode for Selected Contacts AskVG Stop, mute, and change message notifications on iPhone Apple Support (AU)