When a number of impedences are connected together to form a system for performing specific or assigned functions is called a "network" or "circuit".
The various elements of an electric circuit are called its parameters like resistance,inductance,capacitance.
1) lumbed and distributed parameters:
Physically seperate network element like resistance,inductance and capacitance are called lumbed parameters.
A transmission line or cable is an example of distribute parameters as throughout the line they are not physically seperate.
2) Linear and non linear parameters:
linear are constant i.e they donot change with change in voltage or current.
Non-linear parameters change with change in voltage or current.simple resistors,inductors and capacitors are linear elements and their resistance inductances and capacitances donot change with change in applied voltage or the circuit current.semi conductors devices are non-linear parameters.
Passive and active circuit:
Active circuit is a circuit which contains one or more than one sources of emf.An active circuit consists of an active elements like a battery or transistor.
A passive circuit is the one which contains no source of emf in it.