Hello everyone. I have just bought myself a multimeter just for fun. So I've been going around testing voltages and current of things... I have a few questions, and more to surely come later... 1st. When they say Direct Current flows "in one direction" and Alternating Current flows in "both directions", what exactly does this mean? I heard that if you graph both currents, AC will look like a sine wave and DC will be a straight line, with a constant value? Is this what they mean? 2nd. If AC is a sine wave whenever it reaches 0 there should be exactly 0 voltage and current right? Then what happens when it goes negative? How can electricity be negative? 3rd. What causes AC to fluctuate like this? I know that current is the movement of electrons from atom to atom many millions of times, so what does this process look like under AC? Are the electrons literally moving in one direction from atom to atom, then reverse course? 4th. If voltage is the 'pressure' of the current. Then something with a low voltage but very high current can still harm you correct? just like something with a high voltage but not so high current? 5th. What's the voltage/current range you begin to feel something if you touch it and it's live? Obviously most batteries and the like, don't produce enough volts. Thanks guys, been wondering about this stuff all week!