Electricity is the flow of electrons from the negative side, from a baterry for example, to the positive side of the baterry. The negative side is called anode and has a surplus of electrons and the positive side is called cathode and has a deficit of electrons.

Circuit

Electric Current

Symbol is I from the french phrase intensité du courant, (current intensity) and it is measured in Amps(A). Electric Current is the amount of electrons that flows through a conductor at the rate of 1 Coulomb (6.24 X 10^18 elecotrons) per second.

1A = 1C / 1s 

Voltage

The potential energy betwen two points or how strong the electrical current is flowing. Measured in Volts(V) which is how many Joules of energy is transfered for each Coulomb

1V = 1J / 1C

Electrical power

Electrical power which can be calculated with this formula and is measued in Watts:

1W = 1A * 1V

Resistance

A material resistance to electrical current. Measured in Ohms(Ω)