Current
The rate at which electric charge flows.
Dots and arrows represent conventional charge flow in one direction. AC reverses direction during each cycle.
Electric current is the rate of flow of electric charge, measured in amperes. In ordinary grid conductors it produces resistive heating, so equipment has current ratings for specified operating conditions.
Charge crossing a point each second
Current is measured in amperes. In a metal conductor, charge carriers respond to an electric field; a large current does not mean that individual electrons travel from a distant power plant to your home at high speed.
In DC, conventional current has one direction. In AC, its direction reverses periodically. The current carried by a cable or machine contributes to heating, so both normal and fault-current limits matter.
Why it matters
Current ratings determine how much electrical loading equipment can handle under stated conditions.