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There are three things to understand when we talk about electricity: Charge, Current and Voltage.

All objects and materials have charge; it's created by the net of electrons or protons. If there are more electrons, the substance will be negatively charged and if there are more protons, it will be positively charged.

When a non-conductive substance such as plastic gets a charge by having electrons transferred to it, it creates a static electric charge. Such as when you rub a balloon on your head and it sticks or when you put your hand on a Van Der Graff.

Charge is measured in Coulombs and 1 coulomb is equal to the charge of approximately 6.241x1018 electrons.

Now the movement of this charge is called current and it's best to think of it as a river. Just as we measure the amount of water passing a point every second, current is the amount of coulombs passing a point every second. To measure it, we can put an ammeter in place to tell us how many coulombs are passing that point each second. But because physicists and engineers use this measurement so much, they decided to give is a name called an ampere or Amp.

Voltage or potential difference is a bit trickier to understand. The way I like to visualize it is by thinking of a lake that is completely still and therefore has no current. If we were to tilt the lake on its side, the water would rush from the higher gravitational potential to the lower. It's the same concept with Voltage, only instead of gravitational potential difference; we give it an electrical potential difference. We do this by using a battery for example, the battery gives one side of a wire more electric potential energy than the other side, so the current travels through the wire. The more potential difference we give it, the faster the current flows. Just as a steeper waterfall causes water to fall quicker.

But why do we call it potential? Because it is the potential to do work. The unit for the potential to do work is given in Joules per Coulomb and 1 of these is the same as 1 Volt because people decided to give it a name. Lets think of a 1.5V battery connected to a light bulb. What does the 1.5V mean? Well it means if 1 coulomb were to come out of one end of the battery, it could transfer 1.5J of light and heat before it entered the other side again.