Old Electric bulbs were made using tungsten filament.
Whenever an electric current goes through the filament, the filament glows. It may also be known as the electron-emitting element in a vacuum tube. To make the bulb produce more light, the filament is usually made of coils of fine wire, also known as the coiled-coil.
An electric filament bulb may fuse due to many reasons. One reason for a bulb to fuse is a break in its filament. A break in the filament of an electric bulb means a break in the path of the current between the terminals of the electric cell. Therefore, a fused bulb does not light up as no current passes through its filament.
Another reason while electricity passes through the filament of a bulb it produces a heating effect and the filament starts to glow. Now if this heating reaches the temperature of the melting point of the material of that filament it will result in an open circuit situation (normally we call it that the bulb is fused). Also, The fuse breaks the circuit if a fault in an appliance causes too much current to flow.