Difference between AC and DC current

I'll elaborate here.

Exequor was referring to the flow of electrons. In AC, the electrons change direction sinusoidally (in the UK, for mains electricity this frequency will be 50Hz, in the US it's 60Hz I believe). In DC the electrons will carry on flowing around the circuit without changing direction.

In terms of practical differences, AC is used to transmit power over long distances for a few reasons. Firstly, electricity comes out of the generator at the power station as AC. Secondly, it's easier to 'step' up and down the voltage of AC electricity to convert high voltage/low current to high curren/low voltage. To transmit over long distances, AC offers the advantage because resistive losses are minimised with the use of high voltages.

ok, but how does the current change direction in AC, if it were to change direction as you say the 2 wires would alternate between pos and neg polarity and the direction changes, so if i had a loop made of some AC cable, the electrons would flow clockwise for half of the 60hz, and counter clockwise for the other half of the 60hz. But if this was true then touching the pos or neg wire and a ground will result in a shock pulsing at 30hz, because ur only gettin one of the direcions, and even if it wasent pulsing at 30hzm you just plain dont get a shock if you grab the ground and the white lead (the non hot one i think), but ur fine if u touch the ground and the black(hot lead) u get a shock, what gives?

Not sure what you mean.

AC does mean that the electrons change direction constantly. With AC, we don't think of a wire being positive or negative, because of this constant change. If you touch either of the wires and ground, then you will probably get a shock. You won't just be 'getting' one of the directions, - the flow of current is constantly alternating.

I'm not being rude, but can you try and rephrase your question? I don't understand you.

In DC there is a constant polarity over time, where as in AC the polarity changes with time. I don't know how this relates to shocking in AC because at any give point there will be current flowing in one of two directions. If we go back to a simple AC generator it would be seen that if a magnet is spining and the coil is stationary (or vice versa) current would be induced in one direction for a 1/2 cycle and then in the other direction for another 1/2 cycle because the poles of the magnet would have swapped positions. So at 50Hz if you touch the live wire and you are grounded you should get a shock.

The only alternating wire is the live (hot) wire. It alternates between 240v and -240v 50 times a second (50Hz) here in the UK. The neutral (non-hot) wire is effectively tied to ground (0v) which is why you won't get a shock if you hold the neutral (non-hot) and groud wires (they're both, theoretically, at the same potential).

When the live (hot) wire is at a positive voltage, electrons will flow from the neutral (non-hot) to the live (hot), but when the live (hot) is at a negative voltage electrons will flow from the live (hot) to the neutral (non-hot).

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