What is it called when a current skips part of the circuit?

When a current skips part of the circuit, it is called a short circuit. This happens when electricity finds an unintended low-resistance path that bypasses some or all of the circuit’s normal components.

In a working circuit, resistance limits current and electrical energy is delivered to useful devices such as lamps, motors, or heaters. A short circuit can sharply increase the current because the alternate path offers much less resistance. The resulting heat may damage wires, melt insulation, or start a fire.

Circuit breakers and fuses are designed to respond to this danger. A fuse melts when excessive current passes through it, while a circuit breaker opens the circuit mechanically or electronically. A short circuit is different from an open circuit: a short provides an unwanted path with very low resistance, whereas an open circuit contains a break that stops current flow.

The word “short” refers to the shortened electrical path, not to the physical length of the wire.