An RGB LED contains red, green, and blue LEDs in one package. By combining the intensities of these three colors, you can produce nearly any color.t has four pins: one common pin (either anode or cathode) and three pins for controlling the red, green, and blue LEDs.

A 7-segment display is used to display decimal numbers and some characters. It has 8 LEDs arranged in the shape of the digit "8."The pins are categorized into common cathode (all LEDs share a ground) or common anode (all LEDs share a positive connection).16x2 LCD:A 16x2 LCD can display 16 characters per row, with 2 rows.