What is meant by saying that the potential difference between two points is 1 V?

How much energy is given to each coulomb of charge passing through a 6 V battery?

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Let the resistance of an electrical component remain constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?