An electrical grid includes the towering power lines that criss-cross the country. Electricity travels along the lines from power plants to homes and businesses. (Photo: courtesy DOE)

Conductor: A substance that allows electricity to travel through it. Water and aluminum are good examples of conductors.

Insulator: A substance that prevents electricity from traveling through it. Glass and rubber are good examples of insulators.

Voltage: The force of an electrical current, expressed in volts. High voltage electricity travels over power lines, from the power plant to your house. As it passes from one stage to another, the voltage decreases to make it ready for your usage.

Volt: A unit for measuring the force of an electrical current or the stored power of a battery.

Current: The flow of electric charge. A battery is an example of a direct current because the electric current only flows in one direction.

Amperes: A unit used to measure the strength of an electrical current. Amp is short for amperes. Most appliances in your house use 15 or 20 amps of power.

Resistance: The ability of a substance or an electrical circuit to oppose an electrical current passing through it because the electricity is turned into heat.

Ohms: A unit for measuring how much resistance a substance gives to the flow of electricity running through it. For example, when a human body is dry, it has a resistance of 50,000 ohms. However, if the body is wet, the resistance drops to about 100 ohms. When the resistance is lowered, it is easier for a person to become electrocuted or shocked.

Grid: A system for the distribution of electricity over a wide area.

Wattage: An amount of power expressed in watts. For example, the average wattage each month for a handheld hair dryer is 1200. This would be approximately 20 cents each month on an electric bill. If you use a 19-inch color TV for more than six hours a day each month, the average wattage would be 65 and would be 75 cents on your electric bill.

Electricity: A form of energy caused by the motion of electrons and protons.

Proton: A part in the nucleus of an atom that carries a positive electric charge.

Neutron: A part in the nucleus of an atom that has no electric charge.

Electron: A tiny particle that moves around the nucleus of an atom. It carries a negative electrical charge.

Neutral: When an atom has the same number of protons and electrons.

Positive: An atom has a positive charge when an electron gets knocked out of orbit.

Negative: The free electrons can attach onto a neutral atom and make it have a negative charge.