All electrical components can be divided into two main categories as active and passive devices. The categorization is based on components’ capability to produce energy to the circuit.
Those devices or components which required an external source to their operation is called Active Components. For Example Diode, Transistors, SCR etc…
Explanation with Example: As we know that Diode is an Active Components. So it is required an External Source to its operation. Because, If we connect a Diode in a Circuit and then connect this circuit to the Supply voltage., then Diode will not conduct the current Until the supply voltage reach to 0.3(In case of Germanium) or 0.7V(In case of Silicon)
Those devices or components which do not require an external source to their operation is called Passive Components. For Example Resistor, Capacitor, Inductor etc…
Explanation with Example: Passive Components do not require an external source for their operation.
Like a Diode, Resistor does not require 0.3 0r 0.7 V. I.e., when we connect a resistor to the supply voltage, it starts work automatically without using a specific voltage