 So now let's talk about the current equation. In terms of a definition for current, it's the rate of charge flow. In words, I could write that out as the current is equal to the charge per time. In terms of an equation here, well, we've got some interesting symbols. So let's take a look at this. Delta Q is going to be the amount of charge that flows in a certain amount of time, delta t, and that gives me my average current. We use the symbol I for current because, well, C's been used way too much for all sorts of other variables. So now in terms of units, my charge is measured in coulombs. My time is measured in seconds. And so that means I've got a coulomb per second as my unit for charge, for current, excuse me. See, we've got too many C's in here. So that coulomb per second is also redefined to be a new unit with a symbol A where that A stands for amp or ampere. Ampere is a scientist who worked a lot on current, and we shorten it down to just amp a lot of times. Now, if I'm doing calculus-based problems, then I may also see this equation where my derivative of the charge with respect to time gives me my current at a specific time. So rather than looking at the average over a large time span, I can look at it on a moment per moment basis. Most of the time, the current that we're going to be dealing with is a constant current, and so I could use my average current just as well. So those are my equations for current.