Bilateral Network
If the magnitude of current flowing through a circuit element is not affected when the polarity of the applied voltage is changed, then the element is known as a bilateral element.
The bi lateral elements offer the same impedance in both directions.
A resistors is a bilateral element.
A network comprising of one or more number of bilateral elements is known as a bilateral network.
Linear Network:
If the resistance, capacitance or inductance offered by the passive elements does not change with a change in the applied e.m.f or the circuit current the element is called as a linear element.
The linear element shows a linear relation between voltage and current.
The network comprising of one or more linear number of elements is known as a linear network.