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How AI models work
From learning to answering: the ideas behind almost every AI headline, in five short lessons.
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What is an AI model?
An AI model is a program that learned patterns from huge amounts of data. It turns an input, such as a question, into an output, such as an answer, a picture or a decision.
How are AI models trained?
Developers show a model huge amounts of data and let it adjust itself until its predictions improve. Then they fine-tune it with examples and human feedback, so it follows instructions.
What happens when you use an AI model?
Every request runs the trained model on chips in a data centre to produce an answer. This step is called inference: training happens once, inference happens every time someone uses the model.
What is the difference between open and closed models?
An open-weights model can be downloaded and run by anyone; a closed model is used only through its maker’s app or API. Truly open-source AI also shares how it was built.
Frontier models: how are they tested and regulated?
Frontier models are the most capable general-purpose models. Independent testers check makers’ claims, and new laws in the EU and several US states ask their makers for safety plans and incident reports.