A short circuit happens when current finds an unintended low-resistance path. This can allow far more current to flow than the circuit was designed to handle.
Why short circuits are dangerous
A short circuit can overheat wires, damage components, drain batteries quickly, trip breakers, blow fuses, or create fire risk. The seriousness depends on the power source and protection.
How protection helps
A fuse, current limit, circuit breaker, or protected power supply can interrupt or limit excessive current before more damage happens.
In simple terms, a short circuit gives current a path it should not have.