A breadboard is a flat board where a circuit can be tested before being mounted on a circuit board. This board serves as a temporary printed circuit board where components can be easily changed. A typical breadboard is composed of any of the following.
The breadboard is composed of conducting wires placed inside it and connects several of the holes together. The connection inside the breadboard is like the one shown below.
Typically, the voltage supply is placed in the buses or the longer pair of conductor wires at the top and bottom of the breadboard. We connect several of the conducting wires by using solid copper wires. The holes of the breadboards are placed and sized so that practically all electronic components will fit into it. This allows us to make use of the breadboard in order to test electronic circuits before we place them into the printed circuit board.