AI Glossary
What is Large Language Model (LLM)?
An AI model trained on huge amounts of text that can understand and generate human-like language. LLMs power chat assistants like ChatGPT, Gemini, Claude and Copilot.
A large language model learns the patterns of language by reading an enormous amount of text: books, websites, articles and code. When you ask it something, it writes a reply word by word, choosing what is most likely to come next given your request and everything before it.
"Large" refers to the size of the model and the amount of data it learned from.
What LLMs do well: writing, rewriting, summarising, translating, explaining and organising information, and helping with code.
Limits to remember:
- Their knowledge stops at a knowledge cut-off unless they can search the web.
- They can produce confident but wrong answers (hallucinations).
- They only know about your work what you tell them in the chat.
See the lesson What AI Chatbots Really Are.