What do you mean by impedance?

Resistance is a measure of the extent to which a substance opposes the movement of electrons among its atoms.The more easily the atoms give up and/or accept electrons, the lower the resistance, which is expressed in positive real number ohms. Reactance, denoted X, is an expression of the extent to which an electronic component, circuit, or system stores and releases energy as the current and voltage fluctuate with each AC cycle. Reactance is expressed in imaginary number ohms.It is observed for AC, but not for DC.When AC passes through a component that contains reactance, energy might be stored and released in the form of a magnetic field, in which case the reactance is inductive (denoted +jXL); or energy might be stored and released in the form of an electric field, in which case the reactance is capacitive (denoted -jXC). Reactance is conventionally multiplied by the positive square root of -1, which is the unit imaginary number called the j operator, to express Z as a complex number of the form R + jXL (when the net reactance is inductive) or R - jXC (when the net reactance is capacitive). read less