Electric current

An electric current is the rate of flow of electric charge past a point[1]:2[2]:622 or region.[2]:614 An electric current is said to exist when there is a net flow of electric charge through a region.[3]:832 In electric circuits this charge is often carried by electrons moving through a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas (plasma).[4] The SI unit of electric current is the ampere , which is the flow of electric charge across a surface at the rate of one coulomb per second. The ampere (symbol: A) is an SI base unit[5]:15 Electric current is measured using a device called an ammeter.

Volts, Electric potential energy

When a bunch of electrons congregate in one place, their combined charges build up to a certain level of electric potential energy in that object. For example, when I rub this rubber balloon on my wool scarf, it causes a bunch of the electrons from the scarf to jump over on the balloon. Now the balloon is negatively charged, because it has a surplus of negatively charged electrons, and the scarf is positively charged, because it has a shortage of electrons.