The term ELEC. UNITS refers to electrical units, which are used to measure the amount of electricity that is flowing through a circuit. The four most common electrical units are Amps (4 letters), KWs (3 letters), Ohms (4 letters), and RELS (4 letters). Amps measure the rate of flow of electric current, KWs measure the rate of energy transfer, Ohms measure the resistance of a circuit, and RELS measure the ratio of voltage to current.