Question

how is earthing different from fuse

Answer 1

Earthing prevents potential difference building up between the device and surroundings (which would flow through you if you touched it, or arc through the air, or to the nearest chip or sensitive component, blowing the device). The fuse prevents a large current flowing through the circuit.

Answer 2

> Fuse wire is directly connected in series to the load.
> Fuse wire is used to prevent the load from damage in case of excess current.

> Earth wire is not exactly on the main circuit. It is connected the body of load to earth.

> It is used to prevent any kind of shock from the body. If there is any current or voltage on the body of the load due to any fault then this makes a proper path to drop all the current to the earth.