Printed circuit boards were first used in the 1940s to connect discrete components together. By the 1960s, PCBs were widely used in all electronic systems, but still mostly connecting discrete components. Integrated circuits (chip) were emerging and added to the boards, and by the 1980s, PCBs were holding large quantities of chips. Today, printed circuit boards typically connect mostly chips with only a few discrete components, each chip containing from a few thousand up to hundreds of millions of transistors.

A PCB is a printed circuit board, also known as a printed wiring board. It is used in electronics to build electronic devices. A Printed circuit board serves two purposes in the construction of an electronic device; it is a place to mount the components and it provides the means of electrical connection between the components.

A Printed circuit board is a sheet of non-conducting material, usually fiberglass, that has flat wires laid onto it. These wires run between holes in the board into which components will be attached. Most Circuit board  are multilayer boards that have wires on both sides and even on layers sandwiched inside the board

The next step is to "print" the connection diagram onto the PCB. The connection diagram is the wiring required to connect the components. In the very early days of electronics, these connections were in fact done with wires. This is the reason PCBs are also sometimes referred to as printed wiring boards.

Each layer of a Printed circuit board is manufactured in a photographic process that uses a sheet of film to mask the location of wires. This film can be produced by hand or automatically from CAD system output. One popular automatic technique is the use of a photoplotter, which takes the output of a CAD system and produces film to be used in PCB manufacturing. The most popular format for photoplotter control is called Gerber format, created for Gerber Scientific Instrument Company machines [Gerber]. Today other companies' machines accept Gerber format, making this an industry standard.

Next, the PCB is put into an acid bath. The acid bath removes the copper from the board, excepting the areas protected by the resistant material. This process leaves the connections or wiring "printed" on the PCB. Next, holes are drilled in the board to allow the components to be mounted to the PCB and the PCB itself to be mounted to the case protecting the electronics. Finally, a protective coating is applied to the board to prevent corrosion of the copper traces.