Sometimes abbreviated as a board, a PCB is short for printed circuit board and was invented by Paul Eisler while working on a radio in 1936. A PCB is made of plastic or fiberglass that holds ICs and other components. A good example of a PCB found in all computers today is the computer motherboard. The circuit board is most often green from the solder mask that coats the board, however, can be any other color, including red, blue, and even black. The picture is close-up of a printed circuit board. In the picture below, is an example of a circuit board from a Wacom tablet, in the bottom right portion of this board are some ICs that give the board its brains.
What is the biggest circuit board in a computer?
In a desktop computer, the motherboard is the largest circuit board that all other boards and devices connect to and communicate with each other.