Every term the EU AI Act defines

a machine-based system that is designed to operate with varying levels of autonomy and that may exhibit adaptiveness after deployment, and that, for explicit or implicit objectives, infers, from the input it receives, how to generate outputs such as predictions, content, recommendations, or decisions that can influence physical or virtual environments

the combination of the probability of an occurrence of harm and the severity of that harm

a natural or legal person, public authority, agency or other body that develops an AI system or a general-purpose AI model or that has an AI system or a general-purpose AI model developed and places it on the market or puts the AI system into service under its own name or trademark, whether for payment or free of charge

a natural or legal person, public authority, agency or other body using an AI system under its authority except where the AI system is used in the course of a personal non-professional activity

a natural or legal person located or established in the Union who has received and accepted a written mandate from a provider of an AI system or a general-purpose AI model to, respectively, perform and carry out on its behalf the obligations and procedures established by this Regulation

Used inArticle 22Article 54Article 23Article 49Article 13Article 18

a natural or legal person located or established in the Union that places on the market an AI system that bears the name or trademark of a natural or legal person established in a third country

a natural or legal person in the supply chain, other than the provider or the importer, that makes an AI system available on the Union market

a provider, product manufacturer, deployer, authorised representative, importer or distributor

the first making available of an AI system or a general-purpose AI model on the Union market

Used inArticle 5Article 2Article 1Article 49Article 6Article 17

the supply of an AI system or a general-purpose AI model for distribution or use on the Union market in the course of a commercial activity, whether in return for payment or free of charge

Used inArticle 93

the supply of an AI system for first use directly to the deployer or for own use in the Union for its intended purpose

Used inArticle 5Article 49Article 2Article 1Article 6Article 17

the use for which an AI system is intended by the provider, including the specific context and conditions of use, as specified in the information supplied by the provider in the instructions for use, promotional or sales materials and statements, as well as in the technical documentation

Used inArticle 9Article 10Article 13Article 26Article 5Article 7

the use of an AI system in a way that is not in accordance with its intended purpose, but which may result from reasonably foreseeable human behaviour or interaction with other systems, including other AI systems

Used inArticle 5Article 9Article 13Article 14

a component of a product or of an AI system which fulfils a safety function for that product or AI system, or the failure or malfunctioning of which endangers the health and safety of persons or property; for the purposes of this definition, a component fulfils a safety function where its intended purpose is to prevent or mitigate risks to health and safety of persons or property

Used inArticle 6Article 43

a micro, small or medium-sized enterprise as defined in Article 2 of the Annex to Recommendation 2003/361/EC

a small mid-cap enterprise as defined in point (2) of the Annex to Recommendation (EU) 2025/1099

the information provided by the provider to inform the deployer of, in particular, an AI system’s intended purpose and proper use

Used inArticle 13Article 23Article 26Article 24Article 27Article 60

any measure aiming to achieve the return to the provider or taking out of service or disabling the use of an AI system made available to deployers

any measure aiming to prevent an AI system in the supply chain being made available on the market

the ability of an AI system to achieve its intended purpose

the national authority responsible for setting up and carrying out the necessary procedures for the assessment, designation and notification of conformity assessment bodies and for their monitoring

Used inArticle 36Article 28Article 29Article 30Article 33Article 34

the process of demonstrating whether the requirements set out in Chapter III, Section 2 relating to a high-risk AI system have been fulfilled

a body that performs third-party conformity assessment activities, including testing, certification and inspection

Used inArticle 30Article 28Article 29Article 31Article 32

a conformity assessment body notified in accordance with this Regulation and other relevant Union harmonisation legislation

Used inArticle 36Article 37Article 44Article 43Article 75Article 22

a change to an AI system after its placing on the market or putting into service which is not foreseen or planned in the initial conformity assessment carried out by the provider and as a result of which the compliance of the AI system with the requirements set out in Chapter III, Section 2 is affected or results in a modification to the intended purpose for which the AI system has been assessed

Used inArticle 43Article 12Article 25Article 96

a marking by which a provider indicates that an AI system is in conformity with the requirements set out in Chapter III, Section 2 and other applicable Union harmonisation legislation providing for its affixing

Used inArticle 48Article 83Article 16Article 23Article 24

all activities carried out by providers of AI systems to collect and review experience gained from the use of AI systems they place on the market or put into service for the purpose of identifying any need to immediately apply any necessary corrective or preventive actions

Used inArticle 72Article 9Article 17

the national authority carrying out the activities and taking the measures pursuant to Regulation (EU) 2019/1020

Used inArticle 79Article 75Article 46Article 60Article 80Article 74

a harmonised standard as defined in Article 2(1), point (c), of Regulation (EU) No 1025/2012

Used inArticle 41Article 53Article 55Article 43

a set of technical specifications as defined in Article 2, point (4) of Regulation (EU) No 1025/2012, providing means to comply with certain requirements established under this Regulation

Used inArticle 41

data used for training an AI system through fitting its learnable parameters

Used inArticle 15

data used for providing an evaluation of the trained AI system and for tuning its non-learnable parameters and its learning process in order, inter alia, to prevent underfitting or overfitting

a separate data set or part of the training data set, either as a fixed or variable split

data used for providing an independent evaluation of the AI system in order to confirm the expected performance of that system before its placing on the market or putting into service

Used inArticle 10Article 13Article 74

data provided to or directly acquired by an AI system on the basis of which the system produces an output

Used inArticle 12Article 26Article 13Article 50

personal data resulting from specific technical processing relating to the physical, physiological or behavioural characteristics of a natural person, such as facial images or dactyloscopic data

Used inArticle 5Article 26

the automated recognition of physical, physiological, behavioural, or psychological human features for the purpose of establishing the identity of a natural person by comparing biometric data of that individual to biometric data of individuals stored in a database

Used inArticle 5Article 26

the automated, one-to-one verification, including authentication, of the identity of natural persons by comparing their biometric data to previously provided biometric data

the categories of personal data referred to in Article 9(1) of Regulation (EU) 2016/679, Article 10 of Directive (EU) 2016/680 and Article 10(1) of Regulation (EU) 2018/1725

Used inArticle 4Article 7

operational data related to activities of prevention, detection, investigation or prosecution of criminal offences, the disclosure of which could jeopardise the integrity of criminal proceedings

Used inArticle 26Article 5Article 46Article 59Article 72Article 78

an AI system for the purpose of identifying or inferring emotions or intentions of natural persons on the basis of their biometric data

Used inArticle 50

an AI system for the purpose of assigning natural persons to specific categories on the basis of their biometric data, unless it is ancillary to another commercial service and strictly necessary for objective technical reasons

Used inArticle 50

an AI system for the purpose of identifying natural persons, without their active involvement, typically at a distance through the comparison of a person’s biometric data with the biometric data contained in a reference database

Used inArticle 5Article 26

a remote biometric identification system, whereby the capturing of biometric data, the comparison and the identification all occur without a significant delay, comprising not only instant identification, but also limited short delays in order to avoid circumvention

a remote biometric identification system other than a real-time remote biometric identification system

Used inArticle 26

any publicly or privately owned physical place accessible to an undetermined number of natural persons, regardless of whether certain conditions for access may apply, and regardless of the potential capacity restrictions

law enforcement authority’ means: (a) any public authority competent for the prevention, investigation, detection or prosecution of criminal offences or the execution of criminal penalties, including the safeguarding against and the prevention of threats to public security; or (b) any other body or entity entrusted by Member State law to exercise public authority and public powers for the purposes of the prevention, investigation, detection or prosecution of criminal offences or the execution of criminal penalties, including the safeguarding against and the prevention of threats to public security

Used inArticle 5

activities carried out by law enforcement authorities or on their behalf for the prevention, investigation, detection or prosecution of criminal offences or the execution of criminal penalties, including safeguarding against and preventing threats to public security

Used inArticle 5Article 26Article 60Article 78Article 59Article 2

the Commission’s function of contributing to the implementation, monitoring and supervision of AI systems and general-purpose AI models, and AI governance, provided for in Commission Decision of 24 January 2024; references in this Regulation to the AI Office shall be construed as references to the Commission

a notifying authority or a market surveillance authority; as regards AI systems put into service or used by Union institutions, agencies, offices and bodies, references to national competent authorities or market surveillance authorities in this Regulation shall be construed as references to the European Data Protection Supervisor

Used inArticle 36Article 57Article 60Article 16Article 58Article 73

an incident or malfunctioning of an AI system that directly or indirectly leads to any of the following: (a) the death of a person, or serious harm to a person’s health; (b) a serious and irreversible disruption of the management or operation of critical infrastructure; (c) the infringement of obligations under Union law intended to protect fundamental rights; (d) serious harm to property or the environment

Used inArticle 73Article 17Article 26Article 60Article 66Article 76

personal data as defined in Article 4, point (1), of Regulation (EU) 2016/679

Used inArticle 59Article 4Article 2Article 26Article 60Article 7

data other than personal data as defined in Article 4, point (1), of Regulation (EU) 2016/679

Used inArticle 59

profiling as defined in Article 4, point (4), of Regulation (EU) 2016/679

a document that describes the objectives, methodology, geographical, population and temporal scope, monitoring, organisation and conduct of testing in real-world conditions

Used inArticle 60Article 57Article 60

a document agreed between the participating provider and the competent authority describing the objectives, conditions, timeframe, methodology and requirements for the activities carried out within the sandbox

Used inArticle 57Article 58

a controlled framework set up by a competent authority which offers providers or prospective providers of AI systems the possibility to develop, train, validate and test, where appropriate in real-world conditions, an innovative AI system, pursuant to a sandbox plan for a limited time under regulatory supervision

Used inArticle 57Article 58Article 76Article 59Article 62

skills, knowledge and understanding that allow providers, deployers and affected persons, taking into account their respective rights and obligations in the context of this Regulation, to make an informed deployment of AI systems, as well as to gain awareness about the opportunities and risks of AI and possible harm it can cause

Used inArticle 4Article 66Article 95

the temporary testing of an AI system for its intended purpose in real-world conditions outside a laboratory or otherwise simulated environment, with a view to gathering reliable and robust data and to assessing and verifying the conformity of the AI system with the requirements of this Regulation and it does not qualify as placing the AI system on the market or putting it into service within the meaning of this Regulation, provided that all the conditions laid down in Article 57 or 60 are fulfilled

Used inArticle 60Article 9Article 60

for the purpose of real-world testing

a natural person who participates in testing in real-world conditions

a subject’s freely given, specific, unambiguous and voluntary expression of his or her willingness to participate in a particular testing in real-world conditions, after having been informed of all aspects of the testing that are relevant to the subject’s decision to participate

Used inArticle 60Article 61

AI-generated or manipulated image, audio or video content that resembles existing persons, objects, places, entities or events and would falsely appear to a person to be authentic or truthful

Used inArticle 50

any act or omission contrary to Union law protecting the interest of individuals, which: (a) has harmed or is likely to harm the collective interests of individuals residing in at least two Member States other than the Member State in which: (i) the act or omission originated or took place; (ii) the provider concerned, or, where applicable, its authorised representative is located or established; or (iii) the deployer is established, when the infringement is committed by the deployer; (b) has caused, causes or is likely to cause harm to the collective interests of individuals and has common features, including the same unlawful practice or the same interest being infringed, and is occurring concurrently, committed by the same operator, in at least three Member States

Used inArticle 73

critical infrastructure as defined in Article 2, point (4), of Directive (EU) 2022/2557

Used inArticle 59

an AI model, including where such an AI model is trained with a large amount of data using self-supervision at scale, that displays significant generality and is capable of competently performing a wide range of distinct tasks regardless of the way the model is placed on the market and that can be integrated into a variety of downstream systems or applications, except AI models that are used for research, development or prototyping activities before they are placed on the market

Used inArticle 52Article 92Article 91Article 51Article 53Article 54

capabilities that match or exceed the capabilities recorded in the most advanced general-purpose AI models

a risk that is specific to the high-impact capabilities of general-purpose AI models, having a significant impact on the Union market due to their reach, or due to actual or reasonably foreseeable negative effects on public health, safety, public security, fundamental rights, or the society as a whole, that can be propagated at scale across the value chain

Used inArticle 52Article 55Article 93Article 51Article 68Article 90

an AI system which is based on a general-purpose AI model and which has the capability to serve a variety of purposes, both for direct use as well as for integration in other AI systems

Used inArticle 25

any mathematical operation or assignment involving floating-point numbers, which are a subset of the real numbers typically represented on computers by an integer of fixed precision scaled by an integer exponent of a fixed base

a provider of an AI system, including a general-purpose AI system, which integrates an AI model, regardless of whether the AI model is provided by themselves and vertically integrated or provided by another entity based on contractual relations.

Used inArticle 89