EU AI Act glossary: key terms explained simply
Every definition below is the exact text of the Regulation, reproduced word for word.
Where this comes from
All seventeen definitions are quoted verbatim from Article 3 of Regulation (EU) 2024/1689, as published by the European Commission on its own AI Act Service Desk.
Two sources, and nowhere else: ai-act-service-desk.ec.europa.eu and EUR-Lex, which publishes the Official Journal.
Worth saying why that is unusual. The most-cited AI Act website on the internet is run by a private foundation, not by the EU. It is a good resource. It is not the law.
Where we add a plain-English note, it sits in its own orange box and is labelled as ours. Nothing in an orange box is the legal text.
The definitions
AI system
Article 3(1)
‘AI system’ means 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;
provider
Article 3(3)
‘provider’ means 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;
Art50 note, not the legal text: The people who build and sell the model. OpenAI, Anthropic, Google. Almost certainly not you.
deployer
Article 3(4)
‘deployer’ means 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;
Art50 note, not the legal text: The people who use it at work. This is you, and nearly every obligation discussed in public attaches here.
authorised representative
Article 3(5)
‘authorised representative’ means 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;
importer
Article 3(6)
‘importer’ means 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;
distributor
Article 3(7)
‘distributor’ means 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;
operator
Article 3(8)
‘operator’ means a provider, product manufacturer, deployer, authorised representative, importer or distributor;
Art50 note, not the legal text: An umbrella term. Where the text says operator, it means all six roles at once.
placing on the market
Article 3(9)
‘placing on the market’ means the first making available of an AI system or a general-purpose AI model on the Union market;
making available on the market
Article 3(10)
‘making available on the market’ means 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;
putting into service
Article 3(11)
‘putting into service’ means the supply of an AI system for first use directly to the deployer or for own use in the Union for its intended purpose;
substantial modification
Article 3(23)
‘substantial modification’ means 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;
market surveillance authority
Article 3(26)
‘market surveillance authority’ means the national authority carrying out the activities and taking the measures pursuant to Regulation (EU) 2019/1020;
serious incident
Article 3(49)
‘serious incident’ means 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;
deep fake
Article 3(60)
‘deep fake’ means 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;
Art50 note, not the legal text: There is no human-review exemption for these. Editing one does not remove the duty to disclose.
general-purpose AI model
Article 3(63)
‘general-purpose AI model’ means 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;
systemic risk
Article 3(65)
‘systemic risk’ means 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;
downstream provider
Article 3(68)
‘downstream provider’ means 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.
Art50 note, not the legal text: Wrap someone else’s model in your own product and you stop being a deployer and become a provider.
Where the obligations live
- Article 4, AI literacy
- Article 5, prohibited AI practices
- Article 6, classification rules for high-risk AI systems
- Article 50, transparency obligations
- Article 51, classification of general-purpose AI models with systemic risk
- Article 53, obligations for providers of general-purpose AI models
- Article 73, reporting of serious incidents
- Article 74, market surveillance and control
- Article 85, right to lodge a complaint
- Article 99, penalties
One term that is not in Article 3
Proof. The Regulation tells you to disclose, or to have a human review the content and hold editorial responsibility for it. It does not tell you how to show that the review happened. We give you a simple, tamper-evident record of who reviewed a piece of AI-assisted content and when.
Free for journalists, newsrooms, charities, NGOs and public bodies.
