All matter is made up of atoms, which in turn are made up of smaller particles. The three main particles that make up an atom are protons, neutrons, and electrons. Protons have a positive charge and are contained in the nucleus of an atom along with the neutrally charged neutrons. The electrons, which are negatively charged, move around the positively charged nucleus. In some types of atoms, like in a metal, the electrons are only loosely bound to the nucleus and can easily be displaced and move about the other atoms. The flow of of these electrons is what we call a current of electricity.

For electricity to be useful, we need a net flow of electrons to travel in one direction. To do this, we complete a circuit (a closed path for the electrons to move around) and apply an electric potential that drives the electrons to move in one direction.

So where can we get electricity? Electricity is the flow of energy from one place to another. One simple way is by chemical reaction. This is what happens in batteries. The chemicals in a battery react together and can produce an electrical charge. When the battery is placed into a circuit, we get a current of electricity (or the flow of energy!) that can be used to power whatever device it is hooked up to.

Electricity involves a field of physics called electromagnetism. As you might be able to tell from carefully looking at the word, electromagnetism involves the relation between electric and magnetic fields. What this means is that a electrical current can induce a magnetic field around it, and a moving magnetic field can induce a electric field! For example, if you had a piece of wire and began flowing a (relatively high) current through it, you could actually measure a magnetic field around the wire, i.e., if you placed a compass close to the wire, you would no longer be reading the earth's magnetic field, but rather the induced field from the wire!

A similar case also exists in that moving magnetic fields can induce electrical currents. It is the relative motion between the two that is important, so either a conducting wire can be moved through a stationary magnetic field, or a magnet can be moved near a stationary conducting wire. Can you think of ways in which electricity can be generated using the relative motion between magnets and conducting wire? What kind of natural energy sources could we use to cause motion of either magnets or wires relative to each other?

There are a variety of ways to get electricity, but the basic method is to use some form of mechanical energy like pressurized steam or running water to rotate a loop of conducting wire through a magnetic field (like from a magnet). If you do this in the right way, an electrical current can be generated in the conducting loop. It's a little more complicated in practice but this is a basic outline. Have you ever ridden on a bicycle connected to a light bulb (at a museum, perhaps)? This is the method used to light the light bulb.

Electricity is a kind of energy that we convert from other kinds of energy. We have figured out how to convert the energy of burning fuel, running water, wind and even breaking atoms in half, into the energy of moving electrons or "electricity".