(Root Mean Square) Current is also referred to as effective current and is the square root of the average of all the instantaneous currents (current at any point on a sine wave) squared.
The square root of the average of the squares (root-mean-square) of theinstantaneous values. It is the square root of the arithmetical mean of the squares.
(of a.c.) The square root of the average of the squares of the current ( I2) or the voltage ( V2), taken over a complete cycle.