Skip to main content
Reference

IoT Glossary

Plain-English definitions for every IIoT and industrial IoT term you'll encounter — from MQTT to multi-tenancy, SCADA to time-series databases.

A

AMQP

Advanced Message Queuing Protocol. An open standard messaging protocol used in enterprise middleware. In IoT contexts, AMQP is used for reliable, feature-rich message queuing — particularly in enterprise integrations where transactional guarantees are required.

Related:MQTTMessage Broker

Asset Tracking

The use of IoT sensors (GPS, BLE, UWB, RFID) to monitor the real-time location, status and utilisation of physical assets — equipment, vehicles, tools or inventory — across a site or supply chain.

Related:BLEGPSRTLS

API Gateway

A server that acts as the entry point for client requests, routing them to the appropriate microservices. In IoT platforms, API gateways handle device authentication, rate limiting and protocol translation between devices and the cloud.

Related:REST APIMQTTWebhook
B

BLE

Bluetooth Low Energy. A wireless communication protocol designed for short-range, low-power communication between devices. Widely used in IoT for proximity sensing, asset tags and condition monitoring sensors within buildings.

Related:Asset TrackingRTLSZigbee

BMS (Building Management System)

A control system that monitors and manages the mechanical and electrical systems of a building — HVAC, lighting, power, security and fire safety. Modern BMS platforms integrate IoT sensors to provide real-time operational visibility and automated control.

Related:HVACSmart BuildingIIoT Platform

Bandwidth

The maximum data transfer rate of a network connection. Critical in IoT deployments where thousands of devices transmit simultaneously — insufficient bandwidth causes data loss or latency spikes.

Related:MQTTLatencyEdge Computing
C

CoAP

Constrained Application Protocol. A lightweight RESTful protocol designed for constrained devices and networks. CoAP is analogous to HTTP but optimised for low-power, low-bandwidth environments — commonly used with devices on 6LoWPAN networks.

Related:MQTTHTTP6LoWPAN

Cold Storage

In IoT data architecture, cold storage refers to low-cost, high-volume storage for historical data that is infrequently queried. Object storage services (AWS S3, Azure Blob) are typical cold storage tiers, used alongside hot time-series databases for recent data.

Related:Time-Series DatabaseData RetentionData Lake

Cloud-Native

Software designed to run in cloud environments, built with microservices, containers and dynamic scaling. Cloud-native IoT platforms scale elastically with device count rather than requiring fixed infrastructure.

Related:Multi-TenancySaaSKubernetes
D

Data Ingestion

The process of receiving, validating, parsing and storing data from IoT devices into a platform. Robust data ingestion handles multiple protocols, payload formats, authentication schemes, and provides backpressure and deduplication to maintain data integrity at scale.

Related:MQTTHTTPMessage BrokerTime-Series Database

Digital Twin

A real-time virtual representation of a physical asset, process or system. Digital twins are fed by live IoT sensor data and are used for monitoring, simulation, predictive analysis and remote management of physical infrastructure.

Related:IIoT PlatformPredictive MaintenanceData Ingestion

Dashboard

A real-time visual interface displaying IoT data through charts, gauges, maps and KPI tiles. Effective IoT dashboards surface actionable insights rather than raw numbers.

Related:KPIData VisualisationWidget
E

Edge Computing

Processing data at or near the source of generation — on a device, gateway or local server — rather than sending all data to a central cloud platform. Edge computing reduces latency, bandwidth costs, and enables operation during cloud connectivity interruptions.

Related:IoT GatewayFog ComputingData Ingestion
F

Fleet Management

The management of a collection of devices, vehicles or assets as a cohesive group. In IoT, fleet management encompasses device provisioning, OTA firmware updates, remote diagnostics and health monitoring across potentially thousands of endpoints.

Related:OTA UpdateDevice ManagementAsset Tracking

Firmware

Embedded software stored on a device that controls its hardware functions. Regular firmware updates are critical for IoT security — unpatched firmware is one of the most common attack vectors.

Related:OTA UpdateCybersecurityDevice Management
G

GDPR

General Data Protection Regulation. The EU's primary data protection law (applicable in the UK via UK GDPR post-Brexit). IoT platforms that process personal data must comply with GDPR requirements including lawful basis, data minimisation, subject access rights, breach notification and data processor agreements.

Related:Data RetentionRBACAudit Log

Geofencing

Virtual geographic boundaries that trigger automated actions when an asset enters or exits. Used in asset tracking to alert when vehicles leave authorised zones or equipment is moved unexpectedly.

Related:Asset TrackingGPSAlert
H

Heartbeat

A periodic signal sent by a device to confirm it is online and operational. Missing heartbeats trigger alerts in monitoring platforms, enabling rapid detection of device failures or network outages.

Related:UptimeAlertMQTT
I

IoT Gateway

A hardware or software component that bridges IoT devices (often using local protocols like Modbus, BACnet, or Zigbee) with cloud platforms (using MQTT or HTTP). Gateways may also perform local edge processing, protocol translation and data buffering.

Related:Edge ComputingModbusProtocol Translation

IIoT Platform

Industrial Internet of Things Platform. A software stack designed to connect, manage, ingest data from and visualise industrial devices and sensors at enterprise scale. IIoT platforms are distinguished from consumer IoT by their reliability requirements, security posture, integration depth and support for industrial protocols.

Related:SCADADigital TwinMulti-Tenancy
J

JSON

JavaScript Object Notation — a lightweight data format widely used for IoT device payloads due to its human-readability and broad language support. Most REST APIs and many MQTT payloads use JSON.

Related:REST APIMQTTPayload
L

Latency

The time delay between a sensor capturing data and that data appearing in a dashboard or triggering an alert. Sub-second latency is critical for safety monitoring; higher latency is acceptable for trend analysis.

Related:MQTTEdge ComputingReal-Time
M

Message Broker

A server-side component that routes messages between publishers and subscribers using a topic-based system. In IoT, MQTT brokers (Mosquitto, HiveMQ, EMQX) are the most common message brokers, handling device-to-cloud and cloud-to-device message routing at scale.

Related:MQTTPub-SubAMQP

Modbus

A serial communication protocol widely used in industrial automation. Originally developed in 1979 and still ubiquitous in PLCs, SCADA systems, energy meters and HVAC equipment. IoT gateways commonly translate Modbus data into MQTT or HTTP for cloud ingestion.

Related:SCADAPLCIoT Gateway

MQTT

Message Queuing Telemetry Transport. A lightweight publish-subscribe messaging protocol designed for constrained devices and unreliable networks. MQTT's minimal overhead, persistent connections and configurable QoS levels make it the dominant protocol for IoT device-to-cloud communication.

Related:Message BrokerQoSPub-Sub

Multi-Tenancy

An architecture where a single software instance serves multiple independent organisations (tenants) with strict data isolation between them. Multi-tenant IIoT platforms allow systems integrators and MSPs to serve multiple clients from shared infrastructure while guaranteeing that each client's data remains private and inaccessible to others.

Related:White-Label IoTRBACData Isolation
O

OTA Update

Over-the-Air update. The ability to remotely update firmware or software on connected devices without physical access. OTA capabilities are essential for managing large IoT device fleets, patching security vulnerabilities and deploying feature updates at scale.

Related:Fleet ManagementDevice Management
P

PLC

Programmable Logic Controller. An industrial digital computer designed to control manufacturing processes and machinery. PLCs communicate using industrial protocols (Modbus, EtherNet/IP, PROFINET) and are increasingly connected to IIoT platforms via gateways for monitoring and data collection.

Related:SCADAModbusIoT Gateway

Predictive Maintenance

A maintenance strategy that uses real-time sensor data and analytics to predict equipment failure before it occurs. IIoT platforms enable predictive maintenance by continuously monitoring vibration, temperature, electrical signatures and other indicators to detect degradation patterns that precede failure.

Related:Digital TwinIIoT PlatformTime-Series Database

Payload

The data content of a message sent by an IoT device, excluding headers and protocol overhead. Payloads may be JSON, binary or proprietary formats depending on the device and protocol used.

Related:MQTTJSONProtocol
Q

QoS (MQTT)

Quality of Service. In MQTT, QoS defines the delivery guarantee for a message: QoS 0 (at most once, fire-and-forget), QoS 1 (at least once, with acknowledgement), or QoS 2 (exactly once, with a four-part handshake). Higher QoS levels incur more overhead but provide stronger delivery guarantees.

Related:MQTTMessage Broker
R

RBAC

Role-Based Access Control. A security model that restricts system access based on defined roles assigned to users. In IIoT platforms, RBAC ensures that operators, engineers, clients and administrators each have access only to the data and features appropriate to their role.

Related:GDPRMulti-TenancyAudit Log

RTLS

Real-Time Location System. A system that uses radio-frequency technologies (UWB, BLE, WiFi, GPS) to continuously determine and monitor the location of people, assets or equipment within a defined area — typically an indoor facility or campus.

Related:BLEAsset TrackingUWB
S

SCADA

Supervisory Control and Data Acquisition. A control system architecture that uses computers, networked data communications and graphical user interfaces to monitor and control industrial processes. Modern IIoT platforms often complement or extend SCADA systems with cloud-based data aggregation, visualisation and analytics.

Related:PLCModbusIIoT Platform
T

Time-Series Database

A database optimised for storing and querying sequences of values indexed by time. IoT telemetry is inherently time-series data. Purpose-built time-series databases (InfluxDB, TimescaleDB, QuestDB) outperform general-purpose databases for IoT workloads by orders of magnitude at scale.

Related:Data IngestionCold StorageIIoT Platform

Threshold

A defined limit on a sensor reading that, when crossed, triggers an alert or automated action. For example, a temperature threshold of 85°C on a motor might trigger a maintenance alert and reduce machine speed.

Related:AlertRule EngineKPI
U

UWB

Ultra-Wideband. A short-range radio technology capable of centimetre-level indoor positioning accuracy. UWB is used in high-precision RTLS applications — tracking tools, personnel or assets within manufacturing facilities where BLE or WiFi positioning is insufficiently accurate.

Related:RTLSBLEAsset Tracking
W

White-Label IoT

An IoT platform delivered under a partner's own brand — custom domain, logo and colour palette — rather than the underlying vendor's brand. White-label IoT enables systems integrators, MSPs and consultancies to offer enterprise IoT capabilities to clients under their own identity, without building platform infrastructure from scratch.

Related:Multi-TenancyIIoT Platform

Webhook

An HTTP callback that sends real-time notifications to external systems when events occur. IoT platforms use webhooks to push alerts and data to third-party tools like Slack, CMMS systems or custom APIs.

Related:API GatewayAlertIntegration
Z

Zigbee

A low-power, low-data-rate wireless mesh network protocol commonly used in smart building automation — connecting lighting, HVAC sensors, occupancy detectors and access control. Zigbee devices typically connect to IoT platforms via a coordinator gateway.

Related:BLEZ-WaveIoT GatewayBMS

Ready to put this knowledge to work?

See how SIMBIOSYS brings these concepts to life in a real IIoT platform — book a demo with our team.