Large language model (LLM)
Also called: Foundation model
A model trained on vast amounts of text that generates language by predicting the most likely continuation of its input.
A large language model is a pattern-completion system, not a database or a search engine. It has learned statistical associations across billions of examples, which is why it can write fluently about almost anything - and why it can be confidently wrong.
For product people, three properties matter: it has no memory between conversations unless you give it one, its output quality tracks the quality of the context you provide, and it optimises for plausible rather than true.
Example: Claude, ChatGPT and Gemini are consumer products built on top of large language models.