\(V_{Th}\) = The open circuit voltage (\(V_{OC}\)) between terminals is called as Thevenin's voltage. \(R_{Th}\) = The equivalent resistance of the network as seen from the two terminals called Thevenin’s Resistance.

Thevenin’s impedance formula is denoted by \(Z_{TH}\) and it is the equivalent of the impedance of the given circuit when we simplify it into the simpler circuit. \(Z_{TH}=jZ_{TH} \)

\(V_{Th}\) Thevenin's voltage and \(R_{Th}\) Thevenin’s Resistance are the two parameters in Thevenin's circuit

It can be applied to only two terminal linear bilateral networks. Some assumptions are made and situations where this theorem is not applied.

It can be applicable only for linear circuits, other than Resistors, Capacitors, and Inductors, in the circuit this theorem cannot be used. And any two-port networks, unilateral networks also it fails.