Core Concepts
Large Language Model (LLM)
An AI trained on enormous amounts of text to predict what word comes next.
Also known as: LLM,large language model
A Large Language Model (LLM) is an AI system trained on enormous amounts of text — hundreds of billions of words from books, websites, code, and articles — to predict what word should come next given a piece of input. That single trick, repeated thousands of times in a response, is the entire foundation of ChatGPT, Claude, Gemini, and every other modern AI chatbot. LLMs do not "look things up" — they predict patterns. That is why they are fluent and creative but also why they sometimes confidently make things up (hallucinations). LLMs are not databases, they are pattern recognisers trained to sound like the text they were trained on.
