Ampere: It is the S.I. unit of current. If a current flows in a conductor of resistance of 1Ω, when the potential difference across its ends is 1 volt, the current is said to be 1 ampere, i.e.,
1 ampere = 1 volt/1 ohm
Volt: It is the S. I. unit of potential difference. If a current of 1 ampere flows in a conductor of resistance 1 ohm, then potential difference across its ends is said to be 1 volt, i.e.,
1 volt = 1 ampere × 1 ohm.