A circular- or square-shaped pad that provides navigation keys for the four directions: up, down, left and right. These are the equivalent of the "arrow keys" on a computer keyboard and are used for navigating the user interface.
An enhanced version of the D-pad called an 8-way D-pad allows for scrolling diagonally as well.
Some D-Pads have a center button usually called "select" or "OK". It is used to select a highlighted item in the user interface.