Electrical and Electronics Engineering Glossary

Published on August 6, 2026 by Staff Writer

A technician wearing protective gloves and a blue lab coat carefully examines electronic circuit boards in a laboratory.

Your phone charger, washing machine and many other everyday devices rely on electrical and electronic systems. Engineers, technicians, students and manufacturers use a shared vocabulary to explain how those systems manage, convert and measure electricity.

That terminology also appears in electrical code training, electrical safety training and work involving solar and photovoltaic systems. Learning these terms can make it easier to read circuit diagrams, follow laboratory instructions, compare components and explain how a device works.

It can also provide a useful foundation for professionals completing licensing and continuing education courses. This glossary explains 40 common electrical and electronics engineering terms in clear, practical language.

Common Electrical and Electronics Engineering Terms

AC Input

An electrical input supplied by alternating current, which changes direction periodically and commonly operates at a frequency of 50 or 60 hertz.

AC/DC Converter

A circuit or power supply that changes alternating current into direct current for electronic equipment.

Accuracy

The degree to which a measured value agrees with the true or accepted value.

Ampere (A)

The standard unit used to measure electric current, or the rate at which electric charge flows through a circuit. Commonly called an amp.

Analog-to-Digital Converter (ADC)

A circuit that converts a changing analog signal into digital data.

Bootstrap Circuit

A circuit that briefly raises the voltage so that a transistor between the positive power supply and the load (the "high side" of a circuit) can turn on properly. The low side of a circuit is the portion between the load and ground.

Brushed DC Motor

A motor that uses brushes and a rotary switch (commutator) to send current to windings on its rotating section. The commutator also changes alternating current to direct current.

Brushless DC Motor (BLDC motor)

A motor that uses electronic controls instead of brushes to switch current through stationary windings and turn a permanent-magnet rotor.

Buck-Boost Converter

A DC/DC converter that can produce an output voltage above or below its input voltage.

Charge Pump

A DC/DC converter that transfers energy through switched capacitors rather than through an inductor.

Circuit Breaker

A resettable protective device that causes a gap in a circuit when current exceeds a safe level.

Clearance

The shortest distance through air between two conductive parts, maintaining enough separation to prevent arcing or electrical breakdown.

Closed-Loop Control

A control method that measures a system's output and uses the result to adjust its input.

Continuous Conduction Mode (CCM)

An operating mode in a switching power converter in which current through the inductor never falls to zero during a switching cycle.

Controller Area Network (CAN)

A communication system that allows electronic control units (controllers) within a vehicle, machine or other system to exchange data over a shared connection.

Coupled Inductor

Two or more coils linked by a shared magnetic field, so changes in current through one coil create voltage in another.

Creepage

The shortest path along the surface of an insulating material between two conductive parts. Used to assess the risk of leakage current or surface electrical breakdown.

Current Limit Threshold

A preset current level at which a circuit automatically reduces or interrupts its output to protect components.

Current-Mode Control

A power-converter control method that uses measured current to determine when switching occurs.

DC/DC Converter

A circuit that changes one direct-current voltage level into another.

Digital-to-Analog Converter (DAC)

A circuit that converts digital data into a corresponding analog voltage or current.

Diode

A two-terminal semiconductor component that conducts current mainly in one direction.

Drift

An unwanted gradual change in a circuit or sensor's output caused by temperature, aging, power-supply changes or other operating conditions.

Driver

A circuit that provides enough voltage or current to operate another component, such as a transistor, motor or LED.

Electric Motor

A device that converts electrical energy into rotary mechanical motion through magnetic forces.

Electrical Isolation

The separation of two circuits so current does not flow directly between them, often for safety or to reduce electrical interference.

Feedback Voltage

A portion of a circuit's output voltage returned to a controller for comparison with a reference level.

Flyback Converter

A power converter that stores energy in a transformer and then transfers it to an electrically isolated output.

Gallium Nitride (GaN)

A semiconductor material used in high-speed, energy-efficient power and radio-frequency electronics.

Harmonic Distortion

An unwanted change in a waveform caused by additional frequencies that are multiples of the original frequency.

I²C (Inter-Integrated Circuit)

A two-wire communication system that uses one clock line and one data line to connect controllers with other electronic devices.

Inductor

An electronic component that stores energy in a magnetic field when current flows through it.

Inverter

A circuit that converts direct current into alternating current, often with controlled voltage and frequency.

Jitter

Small, unwanted variations in the timing of the transitions, or "edges," where a digital signal (e.g. of a digital clock) changes between its low and high voltage levels.

LED Driver

A circuit that regulates the current or voltage supplied to one or more light-emitting diodes.

Linear Regulator

A voltage regulator that maintains a steady output by dissipating excess input voltage as heat.

Microcontroller (MCU)

A compact integrated circuit containing a processor, memory and input/output hardware for controlling a device.

MOSFET

A type of transistor commonly used to switch or amplify electronic signals and control electrical power.

Ohm (Ω)

The standard unit used to measure electrical resistance, or how strongly a material or component opposes the flow of electric current.

Pulse-Width Modulation (PWM)

A method of controlling average power by changing the proportion of time a signal remains on during each cycle.

Resistance

The opposition a material or component provides to the flow of electric current. Resistance is measured in ohms (Ω).

Semiconductor

A material whose ability to conduct electricity falls between that of a conductor and an insulator and can be controlled by adding impurities, applying voltage or changing temperature. Used to make components such as diodes, transistors and integrated circuits.

Transformer

A magnetic component that transfers AC electrical energy between coils. It can raise or lower voltage and provide electrical isolation.

Watt (W)

The standard unit used to measure electrical power, or the rate at which electrical energy is transferred or used. One watt equals one volt multiplied by one ampere.

Volt (V)

The standard unit used to measure electric potential difference, commonly called voltage.

Additional Readings on Electronics

These resources offer further reading on circuits, electronic components, soldering, semiconductor technology and electrical safety.