What‌ ‌is‌ ‌potential‌ ‌difference‌ ‌or‌ ‌voltage?‌

Hint: This‌ ‌is‌ ‌a‌ ‌very‌ ‌simple‌ ‌topic‌ ‌that‌ ‌is‌ ‌given‌ ‌in‌ ‌the‌ ‌question.‌ ‌You‌ ‌could‌ ‌give‌ ‌the‌ ‌various‌ ‌known‌ ‌definitions‌ ‌that‌ ‌are‌ ‌used‌ ‌for‌ ‌potential‌ ‌difference‌ ‌or‌ ‌the‌ ‌voltage.‌ ‌You‌ ‌could‌ ‌also‌ ‌give‌ ‌its‌ ‌SI‌ ‌unit‌ ‌also‌ ‌give‌ ‌the‌ ‌definition‌ ‌of‌ ‌1SI‌ ‌unit‌ ‌of‌ ‌potential‌ ‌difference.‌ ‌Also,‌ give ‌ ‌ mathematical ‌ ‌expression ‌ for ‌ given ‌ quantity.

Complete step-by-step solution:
In the question we are asked to find out what potential difference is. Potential at a point is the energy required to bring a unit charge from infinity to an arbitrary point. And potential difference is the difference in this potential between those points. Voltage is also equivalent to potential difference and is measured in volts (V). Voltmeter is the device that is used normally to measure potential difference between two points.
Potential difference or the voltage can be given by Ohm’s law that can be given by,
$V=IR$
One volt potential difference can be otherwise defined as equivalent to one joule of energy used by one coulomb of charge in order to flow across two arbitrary points.
We see that potential difference is indeed a location dependent quantity. Mathematically we could express potential difference as,
$\Delta V=\dfrac{W}{q}$
Where, W is the work done to bring the charge q across the given two points.

Note: You may be familiar with the fact that the potential difference across two resistors that are connected in parallel and in series is very different. This is because for parallel connection, we are actually measuring the potential difference between the same points. But for series connection, only one of the points is common to both resistors.