AI glossary

The words you will meet most often, without the jargon.

AI (artificial intelligence)
Computer systems that perform tasks usually associated with human intelligence, such as understanding language or recognising images.
Machine learning
A way of building AI where systems learn patterns from data instead of following fixed rules.
Deep learning
Machine learning that uses many-layered neural networks to find complex patterns.
Neural network
A computing model loosely inspired by the brain, made of connected layers of simple units.
Large language model (LLM)
An AI model trained on huge amounts of text to understand and generate language.
Generative AI
AI that creates new content such as text, images, audio or code.
Prompt
The instruction or question you give an AI tool.
Token
A small chunk of text, such as a word or part of a word, that a model reads and produces.
Context window
The amount of text a model can consider at one time.
Hallucination
A confident but false or invented answer produced by an AI model.
Training data
The examples a model learns from.
Fine-tuning
Further training of an existing model on specific data for a particular task.
RAG (retrieval-augmented generation)
A method where a model looks up relevant documents before answering, to ground its response.
AI agent
An AI system that can plan and take actions, such as using tools, to complete a goal.
Multimodal
Able to work with more than one type of input, such as text, images and audio.
Bias
Systematic unfairness in outputs, often reflecting patterns in the training data.
Inference
The stage when a trained model produces an answer to your request.
Open-weight / open-source model
A model whose weights, and sometimes code, are published for others to run and adapt, under specific licences.
Parameter
An internal value a model adjusts during training; models can have billions of them.
Alignment
Work to make AI systems behave in line with human goals and values.