A PCB is a narrow board constructed from laminated materials, such as epoxy composites or fiberglass. Connecting the various transistors, resistors, and integrated circuits on the PCB are conductive paths that are engraved or "written" onto the board.

Both desktop and mobile PCs use Circuits. Many interior computer parts, including video cards, driver cards, network interface cards, and extension cards, are built on top of them. All of these parts are linked together by the motherboard, which is a printed circuit board.

Despite being frequently linked with computers, PCBs are actually used in a wide variety of other electrical products. One or more printed circuit boards are typically found in most Televisions, radios, digital cameras, smartphones, and iPads. Despite having a comparable appearance to PCBs found in desktop computers and other big gadgets, PCBs used in mobile devices are usually smaller and have more intricate circuits.