Common Anode: In this type of display, all the anodes of the LED segments are connected together and are common to all the digits. Each segment is controlled by a cathode, which is connected to a specific pin of the display driver. When a segment is turned on by applying a low voltage to its respective cathode pin, the common anode supplies a high voltage to illuminate the segment.

Common Cathode: This is the opposite of the common anode display. Here, all the cathodes of the LED segments are connected together and are common to all the digits. Each segment is controlled by an anode, which is connected to a specific pin of the display driver. When a segment is turned on by applying a high voltage to its respective anode pin, the common cathode is grounded to illuminate the segment.

Dual Common Anode/Cathode: This type of display has two sets of common connections, one for the anodes and one for the cathodes. It allows for the display of two digits simultaneously and is commonly used in applications where multiple digits need to be displayed.

Tri-color: Tri-color 7 segment LED displays have three LEDs per segment, usually red, green, and blue. By varying the intensity of each color, different colors can be displayed. This type of display is commonly used in applications where color coding or dynamic color changes are required.

High Brightness: High brightness 7 segment LED displays are designed to produce a brighter output compared to standard displays. They are commonly used in applications where the display needs to be visible in bright ambient lighting conditions or from a distance.

Surface Mount: Surface mount 7 segment LED displays are designed to be mounted directly onto a printed circuit board (PCB) without the need for through-hole soldering. They are smaller in size and are commonly used in compact electronic devices where space is limited.

Overall, the choice of the type of 7 segment LED display depends on the specific application requirements, such as visibility, color, size, and mounting options.