Embedded engineering glossary

PCB

Printed Circuit Board

A PCB (printed circuit board) is a flat board that mechanically supports and electrically connects components via copper traces on an insulating substrate.

HDI PCB

High-Density Interconnect PCB

An HDI PCB uses finer traces and smaller microvias than standard boards, packing more connections into less space for compact, high-performance devices.

Rigid-flex PCB

Rigid-Flex Printed Circuit Board

A rigid-flex PCB combines rigid and flexible circuit sections in one assembly, letting a board fold to fit a 3D enclosure without connectors or cables.

Gerber files

Gerber Format

Gerber files are the standard open format describing each PCB layer — copper, solder mask, silkscreen, drill data — used by fabricators to build the board.

Controlled impedance

Controlled impedance is a PCB technique that sets trace geometry and stackup so high-speed signals see a consistent target impedance, avoiding reflections.

Signal integrity

Signal integrity is how well an electrical signal keeps its shape through a circuit, covering reflections, crosstalk, and timing that can corrupt data.

BMS

Battery Management System

A battery management system (BMS) is electronics that monitor and protect a battery pack, tracking voltage, current, and temperature to prevent damage.

Firmware

Firmware is the low-level software in a device's non-volatile memory that controls its hardware directly, sitting between the hardware and any software.

RTOS

Real-Time Operating System

A real-time operating system (RTOS) is a compact OS that schedules tasks with deterministic timing, guaranteeing time-critical operations meet deadlines.

Bare-metal

Bare-Metal Firmware

Bare-metal firmware runs directly on the microcontroller with no operating system, giving full control and minimal overhead for constrained applications.

Bootloader

A bootloader is a small program that runs first at power-on, initializing hardware and loading firmware, often enabling updates over the air or USB.

BSP

Board Support Package

A board support package (BSP) is the firmware layer — drivers, init code, configuration — that adapts an OS or app to a specific hardware board.

OTA update

Over-the-Air Update

An over-the-air (OTA) update delivers new firmware to a deployed device remotely over its network, letting manufacturers fix bugs and add features.

Embedded system

An embedded system is a computer built into a larger product to perform a dedicated function, combining a processor, memory, and I/O with firmware.

MCU

Microcontroller

A microcontroller (MCU) is a single chip integrating a processor core, memory, and peripherals, designed to run dedicated firmware for real-time control.

MPU

Microprocessor

A microprocessor (MPU) is a processor that relies on external memory and typically runs a full OS like Linux, for devices needing rich UIs or networking.

SoC

System on Chip

A system on chip (SoC) integrates a processor, memory interfaces, and peripherals — sometimes radios or AI accelerators — on one chip to cut cost/space.

SoM

System on Module

A system on module (SoM) packages a processor, memory, and support circuitry as a ready-made board that drops onto a custom carrier, speeding development.

FPGA

Field-Programmable Gate Array

An FPGA (field-programmable gate array) is a chip whose digital logic can be reconfigured after manufacturing, letting engineers implement custom hardware.

Edge AI

Edge Artificial Intelligence

Edge AI is machine learning that runs directly on a device at the network edge rather than in the cloud, delivering low latency and offline operation.

TinyML

Tiny Machine Learning

TinyML is machine learning optimized for low-power microcontrollers with kilobytes of memory, enabling always-on inference within a tiny power budget.

Sensor fusion

Sensor fusion combines data from multiple sensors — accelerometers, gyroscopes, magnetometers — into one estimate more accurate than any sensor alone.

LPWAN

Low-Power Wide-Area Network

LPWAN (low-power wide-area network) is a class of wireless technologies — LoRaWAN, NB-IoT, LTE-M — built for long range and multi-year battery life.

BLE

Bluetooth Low Energy

Bluetooth Low Energy (BLE) is a short-range wireless protocol designed for very low power, widely used to connect battery-powered wearables and sensors.

MQTT

MQ Telemetry Transport (original name)

MQTT is a lightweight publish/subscribe messaging protocol built for constrained devices and unreliable networks, common for sending IoT data to the cloud.

EMC

Electromagnetic Compatibility

EMC (electromagnetic compatibility) is a device's ability to operate correctly without emitting excessive interference or being disrupted by it.

ESD

Electrostatic Discharge

ESD (electrostatic discharge) is the sudden flow of electricity between two charged objects, which can instantly damage sensitive electronics.

Functional safety

Functional safety is the part of a system's safety that depends on electronics and software working correctly, managed through standards like IEC 61508.

DFM

Design for Manufacturability

Design for manufacturability (DFM) is the practice of designing a product to be built reliably and cost-effectively, catching issues before production.

BOM

Bill of Materials

A bill of materials (BOM) is the complete, structured list of every component, part number, and quantity needed to build a product — the master parts list.

NPI

New Product Introduction

New product introduction (NPI) is the process of taking a validated design into volume manufacturing, covering design transfer, pilot builds, and testing.