Electric potential is defined as the work done to move a unit charge from infinity to that point.
Electric potential of a point in an electric field is defined as the work to be done to move a unit positive charge from infinity to that point. What does infinity mean here?
The electric potential at a point is the amount of work done in bringing a unit positive charge from infinity to that point.
Electric potential difference between two points is the work done to move a unit charge from one point to the other.