shooter69:Resistance
Resistance is the property of a component which restricts the flow of electric current. Energy is used up as the voltage across the component drives the current through it and this energy appears as heat in the component. Resistance is measured in ohms.
Impedance
Impedance is a measure of the overall opposition of a circuit to current, in other words: how much the circuit impedes the flow of current. It is like resistance, but it also takes into account the effects of capacitance and inductance. Impedance is measured in ohms.
Impedance is more complex than resistance because the effects of capacitance and inductance vary with the frequency of the current passing through the circuit and this means impedance varies with frequency! The effect of resistance is constant regardless of frequency.
Both are measured in ohms but are differant.
Totally agree, but ohms are ohms, and at a given frequency a conductor simply shows resistance (in ohms). The fact that this resistance is a result of capacitance and inductance is merely the detail of explanation. Resistance is normally a measurement made in DC mode, since there is no frequency changes. Since AC has a frequency variable, then it makes more sense to examine capacitance and inductance effects, as these are the significant factors.