A large language model (LLM) is a Transformer-based AI system trained to generate text by repeatedly predicting the next token — the same technology behind ChatGPT, Claude, Gemini, and DeepSeek.

How an LLM Works: Next-Token Prediction

Think of an LLM as a world-class "sentence completion" engine that has read enormous amounts of text. When you send a prompt, it does not look up an answer in a database. Instead, it calculates, token by token, what is most likely to come next.