How does a fused bulb differ from a normal bulb?

Hint: An electric bulb produces light when the filament inside it gets heated up and glows. To protect the filament from oxidation, the filament is enclosed in a glass bulb. The current is delivered by terminals or wires embedded in the glass to the filament. Mechanical support and electrical connections are provided by a bulb socket.

Complete step by step answer
An electric bulb is a device which, when electricity is passed through its terminals, produces light. With a thin wire attached between them, the bulb has two thick contact wires in the centre. This thin wire is known as a filament. At the base of the bulb, one of the thick wires is connected to the metal case and the other is connected at the centre of the base to the metal tip. These two constitute the terminals. When electricity is passed through the terminals of the bulb, the filament gets heated up and produces light.
It is said that a bulb is fused if the filament is broken. When the filament of the bulb gets broken, then no electric current will pass through it and the bulb is said to be fused. The fused electric bulb won't produce light. To avoid short circuits, the two terminals do not touch each other directly.

Note
A light bulb is a device that produces electricity from light. By sending power through a thin wire called the filament, light bulbs turn electricity into light. The filament is generally made of tungsten, a material that, when electricity is passed through it, emits light. The light emission is due to the high resistance that the material tungsten offers.