Large language model (LLM) explained for business owners
2026-11-10
Definition
A large language model, or LLM, is an AI system trained on very large amounts of text so that it can read a request and produce written language in reply, including summaries, drafts, answers and code.
What to know
ChatGPT, Claude and Gemini are products built on LLMs. The model predicts what text should come next, based on patterns it learned in training. That makes it excellent at drafting, rewriting, sorting and explaining. It also means it can state something false with total confidence, which is called a hallucination. You steer the model with a prompt, and the amount of text it can handle at once is measured in tokens.
An LLM has no knowledge of your business unless you give it. Treat it as a fast, well-read assistant that needs clear instructions and a check on its work. Our guide to writing better prompts for work shows how to steer one.
A hypothetical example
Picture an accounting practice that pastes a long client email into an LLM and asks for a three-line summary and a list of questions to ask back. The model saves ten minutes of reading. The accountant still verifies any figures before replying.
Choosing which model and tools suit you is part of AI strategy.