A breadboard (Steckplatine) is a tool for assembling quick electronics prototypes. The name “breadboard” comes from it’s earliest form, which was literally a wood bread cutting board, where engineers hammered in nails or pins to hold wires together for their prototypes.
Modern breadboard comes in a variety of sizes, but all work in much the same way. They allow you to quickly wire components together without soldering.
Columns or rows of sockets are electrically connected within the breadboard. By inserting two or more pins to share one of these rows or columns allows them to be electrically connected. It’s not always clear whether it is a column or a row connected within a breadboard, so this needs to be checked closely starting your circuit. Many breadboard come with a “powerline” row, for easy access to the negative and positive supply.