dot-matrix display is a low-cost electronic digital display device that displays information on machines such as clocks, watches, calculators, and many other devices requiring a simple alphanumeric (and/or graphic) display device of limited resolution.[1]

The display consists of a dot matrix of lights or mechanical indicators arranged in a rectangular configuration (other shapes are also possible, although not common) such that by switching on or off selected lights, text or graphics can be displayed. These displays are normally created with LCDOLED, or LED lights and can be found in some thin film transistors.[2] The Thin Film Transistors had an active display which allows the dot matrix to display different pixels with different colors at the same time.[3] A dot matrix controller converts instructions from a processor into signals that turn on or off indicator elements in the matrix so that the required display is produced.

https://en.wikipedia.org/wiki/Dot-matrix_display