The three main terms used in electricity are;
(1) Ampere or Amp, which denotes the measure of current flow.
(2) Volt, denoting the measure of electrical force or pressure.
(3) Ohm, a measure of electrical resistance.
The relationship of these is expressed in Ohm's Law which states that Volts = Amps x Ohms.
By knowing any two of these parameters, the third can also be calculated thus:-
Volts = Amps x Ohms
Ohms = Volts divided by Amps
Amps = Volts divided by Ohms
Watts (Power) = Volts x Amps