What potential difference means?

[Instinctlol]

Can someone explain to me what potential difference means?
Lets say point A has a potential of 100 V and point B has a potential of 0 V.
So V_AB would be 100 - 0 = ΔV

But what exactly does that tell us? What does ΔV=100 do ?

 

[sandy.bridge]

Hello,
Potential is the difference between electrical potential energy per unit charge between two points. In other words, it is the work required to move a charge from point A to point B, per unit charge. For example, if 1 joule of energy is used to move a negative charge of 1 coulomb from point A to point B, there exists a voltage difference of 1 V between the points.