Read the text and match There are two types of current: Direct current (DC) and Alternating current (AC).Direct current is a continuous flow of electrons in one direction and it never changes its direction until the power is stopped or switched off.Alternating current constantly changes its direction because of the way it is generated. The term 'frequency' is used to indicate how many times the current changes its direction in one second.Alternating current has a great advantage over direct current because it can be transm itted over very long distances through small wires, by making energy high voltage and low current.There are several quantities that are important when we are talking about electric current. Volts (V) - so named after the Italian physicist Alessandro Volta - measure the difference of electric potential between two points on a conducting wire. Amperes (A) measure the amount of current flowing through a conductor, that is to say the number of electrons passing a point in a conductor in one second.Coulomb (C) measure the quantity of charge transferred in one second by a steady current of one ampere. Power is the rate at which work is performed and it is measured in watts (W). A Kilowatt (kW), which is equal to one housand watts, is used to measure the amount of used or available energy. The amount of electrical energy consumed in one hour at the constant rate of one kilowatt is called kilowatt-hour.