( Voltage ( ( ( ( ( is ( ( the measure ) ( of ( ( potential energy ) ( per ( unit ( of charge ) ) ) ) ) ) ) , ) and ) ( is ( measured ( in Volts ) ) ) ) . ) )
(ROOT (S (NP (NNP Voltage)) (VP (VP (VBZ is) (NP (NP (DT the) (NN measure)) (PP (IN of) (NP (NP (JJ potential) (NN energy)) (PP (IN per) (NP (NP (NN unit)) (PP (IN of) (NP (NN charge))))))))) (, ,) (CC and) (VP (VBZ is) (VP (VBN measured) (PP (IN in) (NP (NNP Volts)))))) (. .)))
Voltage is the measure of  potential energy  per unit of charge , and is measured in Volts.
(ROOT (S (NP (NNP Voltage)) (VP (VP (VBZ is) (RB not) (NP (NP (DT the) (JJ same)) (PP (IN as) (NP (NN energy))))) (, ,) (CC but) (VP (VBZ means) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (NN unit) (NN charge)))))) (. .)))