LLM (large language model)
The engine behind ChatGPT, Claude and Gemini.
The analogy
Imagine someone who has read millions of books, websites and conversations, and has become incredibly good at a single game: guessing the next word. So good that, by chaining one prediction after another, they can write essays, translate, or code. That's an LLM: autocomplete taken to the extreme.
In detail
An LLM is a neural network (usually a transformer) trained on vast amounts of text to predict the next token in a sequence. With enough data and parameters, abilities like reasoning, summarizing and translating emerge. It doesn't look things up in a database — it generates text by computing probabilities.
An example
You type “The sky is” and the model assigns probabilities: “blue” (very high), “cloudy” (high), “green” (very low). To generate a full answer, it repeats that calculation hundreds of times, word by word.