An electronic component is any physical entity in an electronic system used to affect the
electrons or their associated fields in a manner consistent with the intended function of the electronic system. Components are generally intended to be connected together, usually by being soldered to a printed circuit board (PCB), to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly, or in more complex groups as integrated circuits. Some common electronic components are capacitors, inductors, resistors, diodes, transistors, etc. Components are often categorized as active (e.g. transistors and thyristors) or passive (e.g. resistors and capacitors).


Passive components



Passive components can't introduce net energy into the circuit. They also can't rely on a source of power, except for what is available from the (AC) circuit they are connected to. As a consequence they can't amplify (increase the power of a signal), although they may increase a voltage or current (such as is done by a transformer or resonant circuit). Passive components include two-terminal components such as resistors, capacitors, inductors, and transformers.

In electrical, computer or storage systems, passive components are those that do not require electrical power to operate (e.g., not capable of power gain). This could include the chassis, capacitors, resistors or enclosures that do not require electrical power to operate.

E.g. Resistors, Capacitors, Magnetic (inductive) devices, Networks, Transducers, sensors, detectors, Antennas

Active components



Active components are the parts of a circuit that absolutely need a power source to function. These components can increase the electricity in a circuit, though they do not always do so. It is possible that they have a power source in addition to the alternating current flowing through the circuit, though it is not critical that they have one. Ultimately, the key aspect of active components is that they can produce a net increase in the electricity in a circuit, though they do not have to.

E.g.  Semiconductors, Diodes, Transistors, Integrated circuits, Optoelectronic device

For a better understanding of Active components, Passive components look over the list of components which follows on other pages.