Glass fuses are electrical safety devices designed to protect circuits from overloads and short circuits. They consist of a glass tube containing a metal wire or filament that melts when excessive current flows through it, breaking the circuit and preventing damage to electrical components. These fuses are commonly used in household appliances and automotive systems. When a fuse blows, it must be replaced to restore functionality. Glass fuses are often preferred for their visibility, allowing users to easily check if the fuse is intact or needs replacement.