If you are uncertain about the basic qualities and uses of LED’s, please refer to this earlier post providing a basic summation.
7-Segment LED Displays
Seven segment LED displays are the most basic representational format used to create an electronic image or representation. They are composed of seven congruent parts, which can be manipulated to create the Arabic numerals (0-9) as well as the six letter digits (A-F). The most common uses for seven segment displays are for posters, electronic telephone number displays, and pricing displays. Seven segment displays are no longer used as frequently as they were in the past, due to the fact that dot-matrix displays are now the common display method utilized to take full advantage of LED capabilities.
Dot Matrix Displays
Dot matrix displays are now the most common form used to create images and representations with LED’s. Dot matrices consist of a 2-D matrix of LED’s. Through the flow of electricity, it is possible to control each LED individually, which allows for the creation of different objects and symbols.