For containers that protect a building's electrical connections, see Junction box.

An electrical junction may be either a thermoelectricity junction, a metal–semiconductor junction or a p–n junction (p-type semiconductor–n-type semiconductor junction). Junctions are either rectifying or non-rectifying. Non-rectifying junctions are called ohmic contacts. Electronic components employing rectifying junctions include p–n diodes, Schottky diodes and bipolar junction transistors.