Explain the term resistance. Give its $SI$ unit of measurement.

(N/A) Resistance is the property of a conductor to oppose the flow of electric charges through it.
When a potential difference is applied across a conductor,free electrons begin to move,constituting an electric current.
During their motion,these electrons collide with other electrons and atoms of the conductor.
These collisions hinder the flow of electrons,thereby opposing the current.
This opposition to the flow of current is known as resistance.
The $SI$ unit of resistance is the $\text{ohm}$ $(\Omega)$.