Power is how electricity performs work. Whether it’s used to heat a room, run a
motor, or operate a television set, it’s the power that counts. Voltage is the
EMF (electromotive force) that pushes electric current through resistances.
Voltage may be thought of as pressure. Current is amount of electrons that will
perform the work. To quantify power, we use the term Watt, named after James
Watt, the inventor who improved upon the Newcomb steam engine in 1776, which
started the Industrial Revolution.

Power expressed as watts, is computed by multiplying voltage times current,
P=EI. Based upon Ohms Law, there are many other ways to determine power such as
P=I²R, P=E²/R. Many algebraic combinations of P, E, I, and R will be used in
electronics. Memorizing these basic versions now will save you time in the
future.

73… W3SEH