A fuse is also called a current fuse, which is defined by the IEC127 standard as a "fuse-link". It is mainly used for overload protection. When the fuse is correctly placed in the circuit, the fuse will cut off the current when the current abnormally rises to a certain height and heat, thus protecting the safe operation of the circuit.
The fuses invented by Edison more than a hundred years ago were used to protect the expensive incandescent lamps at that time. With the development of the times, the fuses protect the power equipment from overcurrent and overheating, and avoid serious damage caused by internal faults.