An electronic component is a basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. Components are intended to be connected together, usually by soldering to a printed circuit board, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly (resistor, capacitor, transistor, diode etc.) or in more or less complex groups as integrated circuits (operational amplifier, resistor array, logic gate etc.)

Components

Very often electronic components are mechanically stabilized, improved in insulation properties and protected from environmental influence by being enclosed in synthetic resin

Components may be Passive or Active:

• Passive components are those that do not have gain or directionality. In the Electrical industry they are called Electrical elements or electrical components
• Active components are those that have gain or directionality, in contrast to passive components, which have neither. They include Semiconductors (Solid State Devices) and Thermionic Valves (Vacuum Tubes)

Terminals and connectors

Devices to make electrical connection

• Terminal
• Connector
• Socket
• Screw terminal, Terminal Blocks
• Header
• Closed

Cords

Cables with connectors or terminals at their ends

• Power cord
• Patch cord
• Test lead

Switches

Components that may be made to either conduct (closed) or not (open)

• Switch - manually operated switch
• Keypad - small array of pushbutton switches
• Relay - Electrically operated switch. This is a mechanical component, unlike the Solid State Relay
• Reed switch - Magnetically activated switch
• Thermostat - Thermally activated switch
• Circuit Breaker - Over-current activated switch
• Limit Switch - Mechanically activated switch
• Mercury switch
• Centrifugal switch

Resistors

Components used to resist current.

1. See the Transducer section below for resistors used to sense environmental conditions (Thermistor, Photoresistor, RTD...)
2. See the Protection section below for resistors used for current or voltage limiting (MOV, Inrush Limiters...)

• Resistor - fixed value
• Resistor network - array of resistors in one package
• Trimmer - Small variable resistor
• Potentiometer, Rheostat - variable resistor
• Heater - heating element
• Resistance wire - wire of high-resistance material, similar to heating element
• Thermistor - temperature-varied resistor