Electricity is the flow of electrons through a conducting material. The flow of electricity can be used to generate, consume, and transfer power. Due to the nature of electricity, we cannot see it actually flowing. It sometimes helps to imagine electricity as analogous to the flow of water in order to make sense of it. The flow of electricity can be a highly complicated phenomenon so it is very often easier to understand via such analogies. There are three main characteristics of electric flow: voltage, current, and resistance.

**Voltage**: The amount of work available per unit charge. This is analogous to the pressure in a pipe when comparing to fluid flow. Measured in volts (V).

**Current:** The amount of charge per unit time. This is analogous to the flow rate of water in a pipe when comparing it to fluid flow. Measured in amperes (A)

**Resistance:** The resistance against the current. This causes a voltage drop and consumes energy. This is analogous to the friction in pipes when comparing to fluid flow. Measured in ohms (Ω).

The three electrical characteristics of an element are related via Ohm’s Law:

**V = Current * Resistance**