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My understanding of these three things is insanely weak. I just can't seem to grasp some of the concepts of it, no matter how hard I try. Could someone take a crack at explaining them all to me?

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Disclaimer: I have probably have as much or less formal education than you do about electricity and how it works, and am relying almost solely on information I've learned from Wikipedia and my dad, who has an electrical engineering degree.

Let's start with the basics. I'm assuming you know that electricity is the movement of negatively charged electrons moving through a conducting substance, usually some sort of metal. Let's pretend that the stream of electrons through a wire instead water moving through a pipe. After all, they behave similarly and if I'm not mistaken people used to think electricity was some sort of fluid.

Why does electricity flow? Well, in the case of a DC circuit (one that uses as battery, and probably the kind most people learn about first), it works because the battery is forcing the movement of electrons from a positively charged end to a negatively charged end. Since electrons are negatively charged and like charges repel, this is the exact opposite of what they want to do. When they get to the negative end of the battery, they try to go back to the positive end. But since the battery won't let them turn around, they have to travel through the wires all the way back to the positive end, where the process starts over. In the "water in a pipe" analogy, the battery is a pump pumping water up to a water tower, moving it in the exact opposite direction it wants to go and then letting it go when it gets to the end.

Now, voltage. Voltage is a measurement of the forces pushing an electron forwards, like the pressure pushing water through a pump. Voltage is defined as the amount of energy an electrical current is putting out, since this is what keeps the electrons moving, divided by the difference in charge between the two ends of the battery, since this "uses up" some of the energy pushing away from one charge and towards the other, and the "farther apart" the two charges are, the more work this takes. In other words, one volt is equal to one joule (SI unit for energy) per coulomb (SI unit for charge). Think of the energy as pressure pushing water forward in a pipe and the difference in charge in how high up the water tower is, and therefore how much energy is wasted getting it up there.

Next, current. Current can kinda be thought as how fast the current is moving. It's defined as the amount of charges going by any point on the circuit in one second. The SI unit for current, the ampere, or amp, is defined as one Coulomb (again charge, but can also represent a certain number of electrons, I forget exactly how much but I know it's HUGE) per second. Current is going to be pretty much the same all throughout the circuit.

Last but not least, resistance. Resistance is just what it sounds like: something is trying to keep the electrons from flowing. Most of the resistance is from the wire the electrons are moving through. Think of it as the friction of the water moving against the inside of a pipe (which in most cases is pretty rough). There are a few factors that can affect resistance. One of them is the length of the wire. The more pipe water has to flow through, the longer it has to push against that rough edge. Another factor is the thickness of the wire. It's harder to force a lot of water through a narrow pipe. One more is heat, since heat is atoms bouncing back and forth, which kind of gets in the way of the electrons moving. (This is one of the instances where the water analogy doesn't work, since water moves easier the hotter it is, but whatever. Nobody's perfect.) Resistance is measured in Ohms. One Ohm is defined as one volt per amp-the amount of force pushing a current forward divided by how fast it's actually moving. This, incidentally, is Ohm's Law, an important formula in electronics. It can also be written as V(Voltage) equals I(Current, I don't know why they use "I") times R(Resistance).

I hope at least some of that helps.

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That was pretty good, Inglaid.
Pretty close to what I was going to say.

I'm glad to see you've received the "pressure/flow" analogy for voltage and current. That analogy is the one I use when I tutor. It provides a real-world example that's pretty easy to understand.

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If you can't fix it with a hammer, you have an electrical problem.

Yeah, I think each electron is about 1.6 x 10^-19 Coulombs, so that's the relationship between those.

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Only in a series circuit. It's different in different parts of a parallel circuit.

Unfortunately, all those circuit things and the measurements in different parts of them is all the stuff I don't understand.

I think that might've seriously helped. I used to think of voltage as the pipe size and the amperage as how much water's going through the pipe. I've had this explained to me a bunch of times, but I just couldn't get it for some reason.

Think of voltage more as the pressure of the water in the pipe and resistance as being inversely related to size of the pipe.

As the pipe gets smaller (resistance increases), the pressure (voltage) has to increase to send the same amount of water (current) through it.

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If you can't fix it with a hammer, you have an electrical problem.

So electricity is a series of pipes?

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