seven segment display (thing)

Name given to LED displays which use 7 segments, each illuminated by one or more LEDs, to represent the numbers 0 to 9 (and more rarely, 0 to 9 and A to F).

The segments are arranged like this:

 --
|  |
 --
|  |
 --

These displays might be more familiar to you as the displays on your clock radio, digital wristwatch, or microwave oven.

When displaying hexadecimal, the letters formed look like this: A b C d E F. 7-segment displays can display _most_ other letters relatively legibly, but have difficulty with letters like W or M. When all the letters need to be displayed legibly, an alpha-numeric or 'starburst' display is used instead.