Active components can deliver a finite amount of power for some finite amount of time period where passive components can not deliver finite amount of power for some finite amount of time.
Passive elements don't require power from the supply to produce its effect on a signal. They derive the power of the input signal to perform its action. for example, a resistor doesn't require a...
In passive you simply stop doing something life-saving, like stop giving a certain medication. In active you do something that kills, like provide an overdose of a painkiller for instance.
Active immunity: being infected by a live antigen (bacteria/virus) active immunity can be developed through a vacciation.Passive immunity: due to aquiring pre-formed antibodies from another individual