How to Use a Breadboard
A breadboard is a really simple way to put together a circuit. You don’t have to solder, just plug in the components. The breadboard has connections between its holes. Some are vertical connections and some horizontal connections.
It’s common to use the vertical columns on the left and right for connecting the power supply. Each of these columns is connected vertically. So, if you connect 5 volts on the top hole of one of the side columns, you will have 5 volts in all the holes of this column. Some larger breadboards are split into two, so that the upper half of the left and right columns is connected and the lower half is connected. This is indicated by the vertical blue and red lines.
Breadboards are often used to build a prototype or to test a circuit, or a part of a circuit that you are unsure about. It is a better way to use breadboards for testing out new circuits. For example, suppose you want to build a microcontroller circuit that controlled relays with the output pins from the microcontroller. Then you would want a little driver on the output. If you are unsure about this circuit, you could throw it together on a breadboard quickly to make sure it works before you put it into your final design. It is really useful.