There are 13 basic electronic components and many of them have sub-categories. For this article, we will discuss the thirteen. Initially electronic components are broken down into two categories - passive and active. As Wikipedia explains, “an electronic component is any basic discrete device or physical entity in an electronic system used to effect electrons or their associated fields”.

The 13 component types are:

1. Switches

2. Resistors

3. Capacitors

4. Transistors

5. Diodes

6. Inductors

7. Relays

8. Batteries

9. Circuit Breakers

10. Motors

11. Fuses

12. Transformers

13. Integrated Circuits

Switches turn on and off electronic currents or steer currents through other circuitry - with variations like rocker switches, pushbuttons, toggle and the various pole and throw options - there are a lot of switches. There are two variants - mechanical and electrical - and both can be used electronic component builds. Switches have 2 main ratings - voltage that assesses the highest voltage that can be run before short circuits and arc-overs occur and power that sets the maximum power a component can handle while working - this is usually measured in Volt Amps (VA) or Watts.

Resistors control the voltage in a circuit which is measured in Ohms and the value of the resistance can be determined by the colored stripes around the resistor. There are numerous types of resistors including wire wound, surface mount, variable, metal, thick and thin film resistors. As Wikipedia explains, “a resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses”.

Capacitors store electricity that can be used if the voltage drops in a circuit. Capacitors were also called condensers. Unlike resistors, capacitors do not dissipate large amounts of energy and the ideal capacitor would lose none. The Leyden jars were early capacitors - these were created in 1746. Each capacitor has 2 conductors that are separated by a non-conducive area. They can be charged and uncharged and are measured in farads - (F) and its variants pico (pF) and nano (nF).

The earliest transistors were created in 1947 at Bell Labs and won the 1956 Nobel Prize for Physics for John Bardeen and Walter Brattain. Three years later, the MOSFET (metal–oxide–semiconductor field-effect transistor) was also invented at Bell Labs by  Mohamed Atalla with Dawon Kahng. The MOSFET is the most popular transistor used today and has become the basic building block of modern electronics. Interestingly, the word transistor is a contraction of transresistance. The component replaced the cathode tube (vacuum tubes) in most cases, as it was smaller and more heat resistance and demanded less power.

Diodes direct electricity allowing it to flow in one direction but blocking it going the other way. It has high resistance in one direction (the one being blocked) and low resistance in the other. These directions are known as forward (for the low or zero resistance) and reverse for the one blocking (or with high resistance). Early diodes were vacuum tube devices and have developed into a variety of different diodes depending on the usage they were needed for. Thermal, semiconductor, crystal, avalanche, laser and the well known LED (light emitting diode) are just a few types of diodes.

Inductors store energy when an electric charge flows through a magnetic field. They are  two-terminal electronic components. Outlined in Faraday’s Law of Induction any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. Used more in AC equipment and radios - there they allow DC to flow ande block AC current.

Relays are electrically operated switches used originally in the telegraph system. Given the on off nature of relays, they were adapted to the early computer industry, as well as the telephone. They were used for logical operations in computers as they essentially work in a 1 and 0 method. “A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron core (a solenoid), an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, and one or more sets of contacts,” Wikipedia notes.

Batteries store and dispense electricity - the rechargeable ones can do that more than once. Batteries come in varying sizes and use varying metals from zinc to silver-oxide and Lithium. They are also quite adaptable - there have been batteries used on the moon and at the bottom of the ocean.

Circuit breakers, like the name suggests, are used for breaking circuits. Essentially, circuit breakers act as switches controlling the flow of electrical current. This protection of the electric circuit fromThomas Edison patented a fuse in 1890 as part of his  electric distribution system current overload or short circuit differs from a fuse which can only be used once. Breakers can be reset and thus have a much longer life and reduce cost. Thomas Edison was involved with the early circuit breakers. “Circuit breakers are rated both by the normal current that they are expected to carry, and the maximum short-circuit current that they can safely interrupt. This latter figure is the ampere interrupting capacity (AIC) of the breaker.” 

Motors, convert electrical energy into mechanical energy (other types of motors change other energies). The process involves  the interaction of magnetic fields and current-carrying conductors, and was first mapped out in 1821 and were built throughout the 19th century. The more efficient the process the less kilowatts needed to run them. 

Fuses operate to protect electrical circuits from overload and are one time use metal wire or strips. They are made using metals like silver, copper, zinc and aluminum with a predictable resistance. Used in place of circuit breakers, fuses are the older of the two and were developed to protect the early telegraph industry from lightning. Thomas Edison patented a fuse in 1890 as part of his electric distribution system.

Transformers transfer electrical energy from one electrical circuit to another (and even multiple circuits). Electromagnetic induction was developed by Faraday and others. The induction coil was the earliest mass produced transformer, built in Ireland in 1836, five years after Faraday outlined EMF and induction. The ZBD team consisted of Károly Zipernowsky, Ottó Bláthy and Miksa Déri at the Ganz Works in Hungary revolutionized transformers by building the first enclosed unit.

Integrated Circuits or microchips are sets of electric circuits on a small semiconductor material. The very small size and ability of “mass production capability, reliability, and building-block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs”.

There are two basic types of integrated circuits, analog and digital  Analog IC would be integrated circuits that operate in the analog domain (amplifiers,voltage regulators, etc). Digital IC’s would include logic gates, microcontrollers and microprocessors.

Microcontrollers are small computers on a metal-oxide semiconductor integrated circuit chip and are used in remote devices like medical devices, remote controls, appliances and other embeddable devices. Linked back to the transistor, microcontrollers are another electronic component that fell under Moore’s Law. First created in the early 1970s, MOS transistors (as microcontrollers are also known) are used for a wide variety of products. But, the ability to preprogram the MCUs allows manufacturing to reduce the costs as they can be done en masse.

Online Components carry most of the above listed components - use the links in the article or search via the box at the top of the page.