ISO/IEC 20924:2021

ISO/IEC 20924
Edition 2.0 2021-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Internet of things (IoT) – Vocabulary

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from

either IEC or IEC's member National Committee in the country of the requester. If you have any questions about
ISO/IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address

below or your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
ISO/IEC 20924
Edition 2.0 2021-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Internet of things (IoT) – Vocabulary

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 35.020 ISBN 978-2-8322-9588-5

– 2 – ISO/IEC 20924:2021 RLV © ISO/IEC 2021

CONTENTS
FOREWORD . 3

1 Scope . 5

2 Normative references . 5

3 Terms and definitions . 5

3.1 General terms . 5

3.2 Internet of Things specific terms . 9

Bibliography . 12

INTERNET OF THINGS (IoT) –
VOCABULARY
FOREWORD
1) ISO (the International Organization for Standardization) and IEC (the International Electrotechnical

Commission) form the specialized system for worldwide standardization. National bodies that are members of

ISO or IEC participate in the development of International Standards through technical committees established
by the respective organization to deal with particular fields of technical activity. ISO and IEC technical

committees collaborate in fields of mutual interest. Other international organizations, governmental and non-

governmental, in liaison with ISO and IEC, also take part in the work.

2) The formal decisions or agreements of IEC and ISO on technical matters express, as nearly as possible, an

international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested IEC and ISO National bodies.
3) IEC and ISO documents have the form of recommendations for international use and are accepted by IEC and
ISO National bodies in that sense. While all reasonable efforts are made to ensure that the technical content of
IEC and ISO documents is accurate, IEC and ISO cannot be held responsible for the way in which they are
used or for any misinterpretation by any end user.
4) In order to promote international uniformity, IEC and ISO National bodies undertake to apply IEC and
ISO documents transparently to the maximum extent possible in their national and regional publications. Any
divergence between any IEC and ISO document and the corresponding national or regional publication shall be
clearly indicated in the latter.
5) IEC and ISO do not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC and ISO marks of conformity. IEC and ISO are not
responsible for any services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this document.
7) No liability shall attach to IEC and ISO or their directors, employees, servants or agents including individual
experts and members of its technical committees and IEC and ISO National bodies for any personal injury,
property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including
legal fees) and expenses arising out of the publication, use of, or reliance upon, this ISO/IEC document or any
other IEC and ISO documents.
8) Attention is drawn to the Normative references cited in this document. Use of the referenced publications is
indispensable for the correct application of this document.
9) Attention is drawn to the possibility that some of the elements of this ISO/IEC document may be the subject of
patent rights. IEC and ISO shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition ISO/IEC 20924:2018. A vertical bar appears in the margin wherever a
change has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – ISO/IEC 20924:2021 RLV © ISO/IEC 2021

International Standard ISO/IEC 20924 has been prepared by subcommittee 41: Internet of

Things and related technologies, of ISO/IEC joint technical committee 1: Information

technology.
This second edition cancels and replaces the first edition published in 2018. This edition

constitutes a technical revision.

This edition includes the following technical changes with respect to the previous edition:

a) addition of new terms (safety, wearable device, data acquisition functional system,

transport interoperability, etc) which are used in other ISO/IEC IoT related standards;

b) update of some definitions (data, data store, discovery service, etc.) to align with current
usage in other IoT standards.
The text of this International Standard is based on the following documents:
FDIS Report on voting
JTC1-SC41/195/FDIS JTC1-SC41/209/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

INTERNET OF THINGS (IoT) –
VOCABULARY
1 Scope
This document provides a definition of Internet of Things along with a set of terms and
definitions. This document is a terminology foundation for the Internet of Things.

2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 General terms
3.1.1
address
value that can be used to identify an endpoint, which can designate the originating
source or destination of data being transmitted
3.1.2
application
software designed to fulfil a particular purpose
[SOURCE: ISO/IEC 24713-2:2008, 4.1, modified – "program or piece of" has been removed
from the beginning of the definition.]
3.1.3
architecture
set of fundamental concepts or properties of a system in its environment embodied
in its elements, relationships, and in the principles of its design and evolution
[SOURCE: ISO/IEC/IEEE 42010:2011, 3.2, modified – "set of" has been added to the
beginning of the definition.]
3.1.4
asset
physical entity or digital entity that has value to an individual, an organization or a government
[SOURCE: ISO/IEC 27032:2012, 4.6, modified – "anything" has been replaced by "physical
entity or digital entity" at the beginning of the definition.]
entity that has value and is either owned by or under the custody of an individual, an
organization, a government, or other groups

– 6 – ISO/IEC 20924:2021 RLV © ISO/IEC 2021

3.1.5
availability
property of being accessible and usable upon demand by an authorized entity

Note 1 to entry: IoT systems can include both human users and service components as "authorized entities".

[SOURCE: ISO/IEC 27000:2018, 3.7]

3.1.6
characteristic
abstraction of a property of an entity or of a set of entities

[SOURCE: ISO 18104:2014, 3.1.4]
3.1.7
cloud computing
paradigm for enabling network access to a scalable and elastic pool of shareable physical or
virtual resources with self-service provisioning and administration on-demand
[SOURCE: ISO/IEC 17788:2014, 3.2.5]
3.1.8
cloud service
one or more capabilities offered via cloud computing invoked using a defined interface
[SOURCE: ISO/IEC 17788:2014, 3.2.8]
3.1.9
cloud service provider
party which makes cloud services available
[SOURCE: ISO/IEC 17788:2014, 3.2.15]
3.1.10
compliance
characteristic of conformance to rules, such as those defined by a law, a regulation, a
standard, or a policy
3.1.11
component
modular, deployable, and replaceable part of a system that encapsulates implementation and

exposes a set of interfaces
[SOURCE: ISO 14813-5:2010, B.1.31, modified – "that encapsulates implementation and
exposes a set of interfaces" has been deleted from the end of the definition.]
3.1.12
confidentiality
property that information is not made available or disclosed to unauthorized individuals,
entities, or processes
[SOURCE: ISO/IEC 27000:2018, 3.10]
3.1.13
data
symbol or symbols represented in a digital and formalized manner suitable for communication,
storage, interpretation or processing

3.1.14
data store
persistent repository for digital information data

Note 1 to entry: A data store can be accessed by a single entity or shared by multiple entities via a network or

other connection.
3.1.15
digital entity
computational element and/or data element

Note 1 to entry: A digital entity can exist as in several forms, including a cloud service or as a service in a data

centre, or as a network element or as an IoT gateway.
3.1.16
discovery service
service to find unknown resources, entities or services based on a specification of the desired
target
Note 1 to entry: A discovery service can be used by a human user or a digital user.
3.1.17
endpoint
component that exposes or uses one or more network interfaces
3.1.18
entity
thing (physical or non-physical) having a distinct existence
[SOURCE: ISO/IEC 15459-3:2014, 3.1]
3.1.19
functional component
functional building block needed to engage in an activity, backed by an implementation
Note 1 to entry: See also "component", which is a superset containing all functional components and other types
of component that are deployable.
[SOURCE: ISO/IEC 17789:2014, 3.2.3, modified – Note 1 to entry has been added.]
3.1.20
human user
natural person who uses a system

3.1.21
identifier
information that unambiguously distinguishes one entity from other entities in a given identity
context
3.1.22
identity context
environment where an entity can use a set of attributes for identification be sufficiently
identified by a certain set of its attributes and values
3.1.23
information
data that within a certain context has a particular meaning

– 8 – ISO/IEC 20924:2021 RLV © ISO/IEC 2021

3.1.24
interface
shared boundary between two functional components, defined by various characteristics

pertaining to the functions, physical interconnections, signal exchanges, and other

characteristics, as appropriate

[SOURCE: ISO/IEC 13066-1:2011, 2.15, modified – In the definition, "units" has been

replaced by "components"; ", as appropriate" has been deleted from the end of the definition.]

3.1.25
interoperability
ability of two or more systems or applications to exchange information and to mutually use the
information that has been exchanged
[SOURCE: ISO/IEC 17788:2014, 3.1.5]
3.1.26
network
infrastructure that connects a set of endpoints, enabling communication of data between the
digital entities reachable through them
3.1.27
physical entity
entity that has material existence in the physical world
Note 1 to entry: In the Internet of Things reference architecture, the physical entity is the thing to be sensed
and/or actuated by IoT devices or IoT systems.
entity in the physical world that can be the subject of sensing and/or actuating
3.1.28
reference architecture
architecture description that provides a proven template solution when developing or
validating an architecture for a particular solution
architecture framework used as a template when developing or validating an architecture
description for a particular solution
3.1.29
safety
state in which the risk of harm (to persons) or damage is limited to an acceptable level

[SOURCE: ISO 21101:2014, 3.34]
3.1.30
service
distinct part of the functionality that is provided by an entity through interfaces
[SOURCE: ISO/IEC TR 14252:1996, 2.2.2.46, modified – In the definition, "part of the
functionality" has been replaced by "functionality" and "on one side of an interface to an entity
on the other side of the interface" has been replaced by "through interfaces".]
3.1.31
service provider
organization or part of an organization that manages and delivers a service or services to the
customer
[SOURCE: ISO/IEC TR 20000-10:2015, 2.32]

organization that manages and delivers a service or services to customers

[SOURCE: ISO/IEC 20000-10:2018, 3.2.24]

3.1.32
stakeholder
individual, team, organization, or classes thereof, having an interest in a system

[SOURCE: ISO/IEC/IEEE 42010:2011, 3.10]

3.1.33
tag
human- or machine-readable mark, or digital identity used to communicate information about
an entity
Note 1 to entry: A tag can contain information that can be read by sensors to aid in identification of the physical
entity.
3.1.34
trustworthiness
property of deserving trust or confidence
ability to meet stakeholder expectations in a demonstrable, verifiable and measurable way
Note 1 to entry: Depending on the context or sector, and also on the specific product or service, data, and
technology used, different characteristics apply and need verification to ensure stakeholders’ expectations are met.
Note 2 to entry: Characteristics of trustworthiness include, for instance, reliability, availability, resilience, security,
privacy, safety, accountability, transparency, integrity, authenticity, quality, usability and accuracy.
Note 3 to entry: Trustworthiness is an attribute that can be applied to services, products, technology, data and
information as well as, in the context of governance, to organizations.
3.1.35
virtual entity
digital entity that represents a physical entity
3.1.36
wearable device
electronic device intended to be located near to, on or in a body
Note 1 to entry: Wearable devices often have a variety of sensing abilities, but limited power capacity
constraining communication and data processing abilities. As critical devices of the IoT, it is considered that the
communication between wearable devices and a network might not require any human intervention. Wearable
devices include electronic devices usable by humans, animals, and other organisms.

3.2 Internet of Things specific terms
3.2.1
actuator
IoT device that changes one or more properties of a physical entity in
response to a valid an input
Note 1 to entry: The change can be nonmechanical in nature.
3.2.2
data acquisition functional system
system for gathering required data from a group of sensors, and
assembling them into messages for delivery to a component

– 10 – ISO/IEC 20924:2021 RLV © ISO/IEC 2021

3.2.3
digital user
digital entity that uses an IoT system

Note 1 to entry: Digital user includes automation services that act on behalf of human users.

3.2.4
Internet of Things
IoT
infrastructure of interconnected entities, people, systems and information resources together

with services which processes and reacts to information from the physical world and virtual

world
3.2.5
IoT conceptual model
common structure and definitions for describing the concepts, relationships, and behaviour
within an IoT system
3.2.6
IoT device
entity of an IoT system that interacts and communicates with the physical world through
sensing or actuating
Note 1 to entry: An IoT device can be a sensor or an actuator.
3.2.7
IoT domain
major functional group of an IoT system
Note 1 to entry: Every entity in an IoT system participates in one or more IoT domains and is said to be included
or contained by that domain.
Note 2 to entry: The IoT domain consists of six domains: user domain, operation & management domain,
application & service domain, resource access & interchange domain, sensing & controlling domain, physical entity
domain.
3.2.8
IoT gateway
entity of an IoT system that connects one or more proximity networks and the IoT devices on
those networks to each other and to one or more access networks
3.2.9
IoT system
system providing functionalities of Internet of Things IoT

Note 1 to entry: An IoT system is inclusive of IoT can include, but not be limited to, IoT devices, IoT gateways,
sensors, and actuators.
3.2.10
IoT trustworthiness
property of deserving trust or confidence within the entire lifecycle of an Internet of Things
implementation to ensure security, privacy, safety, reliability and resiliency
trustworthiness of an IoT system with characteristics including security, privacy, safety,
reliability, and resilience
3.2.11
IoT user
user of an IoT system
Note 1 to entry: An IoT user can be a human user or a digital user.
...