breadboard fundamentals
The term breadboard is derived from an early form of point-to-point construction; and in particular the practice of constructing simple demonstration circuits (usually using valves/tubes) on a convenient wooden base, (similar to a cutting board).
A breadboard (solderless breadboard, plugboard) is a reusable solderless device used to build a (generally temporary) prototype of an electronic circuit and for experimenting with circuit designs. This is in contrast to stripboard (veroboard) and similar prototyping printed circuit boards, which are used to build more permanent prototypes or one-offs, and cannot easily be reused. A variety of electronic systems may be prototyped by using breadboards, from small circuits to complete central processing units (CPUs).
Pad per hole perfboard (Source)
You can also find perfboard types with various copper patterns that connect multiple holes. In the image below, the white markings on the top of the board tell you where copper is on the bottom side. This particular type has a complicated pattern: there are two bus strips down the center of the board, 2-hole pads on the edges of the board, and 3-hole pads and pad-per-holes between the two.
A thin plastic board used to hold electronic components (transistors, resistors, chips, etc.) that are wired together. Used to develop prototypes of electronic circuits, the boards can be reused for future jobs. Breadboards can also be used to create one-of-a-kind systems, although commercial products placed on printed circuit boards are typically much more robust and can handle greater frequencies.
The breadboard contains spring clip contacts typically arranged in matrices with certain blocks of clips already wired together. The components and jump wires (assorted wire lengths with pins at both ends) are plugged into the clips to create the circuit patterns. The boards also typically include metal strips along the side that are used for common power rails and signal buses.