A pager is a simple telecommunications device for short messages. The doctors of Grey Sloan Memorial Hospital and St. Ambrose Hospital use them to communicate with each other quickly when there is an emergency.
The sparkle pager is a glittery pager that must be paged when a surgery is received by another resident. The sparkle pager owner then has the ability to take the surgery.
In Where the Wild Things Are, Meredith Grey won the sparkle pager in a competition with Alex, Izzie, and Cristina. The sparkle pager was decorated many years ago by an unknown figure. (Not Bailey with a Bedazzler)
In Freedom, Part 1, Meredith Grey gives the sparkle pager to Cristina to cheer her up.