>>11022813We have a simple DC circuit and also a pipe network.
Voltage => height of the pipe over the ground or a pre-defined datum (feet of head)
Current => flowrate of water (gallons per minute or cubic feet per second)
Coulombs => a quantity of water (cubic feet, gallons, acre-feet, whatever). Sometimes water backs up into a reservoir, so it makes less sense to talk about the flow of water (quantity per second) and just talk about quantity. This is what capacitors and dams accomplish.
Joules => joules. A joule or a BTU or a lbs-ft or a psi-cu.ft are all units of energy. Energy is very closely related to voltage/hydraulic head, but has a different unit. Energy is an amount of work that you can accomplish.
kWatt => Power. This is energy delivered per time. If you stick a water wheel in a rushing river, the shaft of the wheel will transmit a certain number of joules per second. If lifting a box is work, lifting a box within a given time is work per time, or power.
>>11022786Voltage is just an intensive version of potential energy.
