Solderless breadboards are great for experimenting with new circuits or making prototypes because the parts can be easily changed. They are useful for both analog and digital circuits at low and moderate frequencies. Breadboards come in various sizes and configurations. Below is an example.
BreadBoard Full Size
BreadBoard Half Size (transparent)
BreadBoard Mini Size (Green)
Breadnoard Mini Size (White)
Breadnoard Half Size
How a Breadboard Works
The best way to explain this question is to take it apart and see what is inside. You can see lots of vertical and horizontal of metal strips on the bottom of the breadboard.
Every breadboard is made of three sections: two set of very long power rails and the large middle section that is full of those 5-hole-long terminal strips. Only the mini and tiny sized breadboards do not have power rails.
- Terminal Strips
- On the middle section of the board
- Each 5 hole columns is a group and connected together
- The holes between columns is not connected
- Power Rails (also called Bus Strips)
- Two strips of holes running along the long edges of the board.
- Each side contains two columns and usually will be labeled with a "+" and a "-", or have a red and blue or black strip to indicate the positive and negative power sources.
The strips of metal provide electrical connection between holes in the terminal strip (shorter columns). Pushing the legs of two different components into the same column joins them together electrically. A deep channel running down the middle indicates that there is a break in connections there, meaning, you can push a chip in with the legs at either side of the channel without connecting them together.
Full sized and half sized breadboards have two strips of holes running along the long edges of the board that are separated from the main grid. These have strips running down the length of the board inside and provide a way to connect a common voltage. They are usually in pairs for +5 or +3.3 volts and ground. These strips are referred to as rails and they enable you to connect power to many components or points in the board.