AI system

Article 3(1) of the AI Act defines an AI system as a machine-based system designed to operate with varying levels of autonomy, that may adapt after deployment and that infers from the input it receives how to generate outputs (predictions, content, recommendations or decisions) that can influence physical or virtual environments.

The key word is infer. A program that only executes fixed rules written by a person (an Excel formula, an "if A then B") is usually not an AI system. A model that learns from data, a chatbot or a recommender system is. The Commission published guidelines in 2025 to help tell them apart.

Knowing which tools in your company are "AI systems" is the first step of any compliance plan: without that inventory you cannot classify risks or assign obligations.