I'm currently getting started to learn about electrical engineering, and I'm having some difficulty separating voltage from current.
I have seen a couple of times that a battery is compared to two water tanks, one filled with lots of water, and the other one empty. Between them is a hose that connects them.
Now there is some amount of water that flows through the hose in a given amount of time, e.g. 1 liter per minute. Is this equivalent to current? In other words: Is the amount of electrons that are "transferred" in a given amount of time measured in Ampere? Is this right? So, again in other words: Is current basically comparable to something such as kilometers or miles per hour, so is current the speed of the electricity?
As far as I understood voltage is the difference between the amount of water in the two tanks. So it's like the pressure. In the beginning, when one tank is full, and the other one is empty, the pressure is higher, than after some time, when some water has already flown. Does this mean that the voltage of a 9V battery is only 9V in the beginning of its lifetime, and gets less over time?
Now I wonder about their relationship: If the voltage is higher, it does not necessarily mean that the electrons flow faster, only that there is more pressure behind them to get over resistances. Right?
And, when we are now talking about resistance: A resistance is comparable to someone who steps onto the hose and lowers the amount of water that can flow. Transferred, does this mean that a resistance lowers the current, but not the voltage?
Sorry if all these questions seem to be dumb, but as I said, I'm really at the very beginnings, and I'm trying to get the concepts right.