What is Large Language Model (LLM)?
An LLM is an AI model trained on huge amounts of text that predicts language well enough to write, summarise, translate, and answer questions.
A large language model is the engine behind almost every AI writing, chat, and coding tool you compare. It is trained on billions of sentences from books, websites, and code, and it learns one deceptively simple skill: predicting the most likely next chunk of text. Repeated at scale, that skill turns into drafting emails, explaining contracts, translating languages, and writing working code. When you evaluate tools, the LLM matters because it sets the ceiling on quality — a tool running on a frontier model like GPT, Claude, or Gemini will usually reason better than one running a small, cheap model. What differentiates products built on the same model is everything around it: the interface, the prompts baked in, the data it can access, and the integrations. LLMs do not look things up unless connected to search or a knowledge base, they do not truly know facts, and they can state wrong answers confidently. That is why context windows, retrieval, and hallucination rates are the specs worth comparing rather than raw marketing claims about intelligence.
Also known as
- large language model
- foundation model
- LLM
Related tools
- ChatGPT — The most versatile AI assistant for writing, research, and brainstorming.
- Claude — Thoughtful, safety-focused AI assistant with excellent reasoning.
- Google Gemini — Google's multimodal AI with real-time information access.
- Perplexity AI — AI search engine that gives direct answers with cited sources.
- GitHub Copilot — AI pair programmer that writes and suggests code inside your editor.
Related terms
- Generative AI — Generative AI is any AI that creates new content — text, images, audio, video, or code — rather than only analysing existing data.
- Context Window — The context window is the maximum amount of text, measured in tokens, an AI model can consider at one time.
- Hallucination (AI) — A hallucination is when an AI tool produces confident, fluent output that is factually wrong or entirely invented.
- Prompt Engineering — Prompt engineering is the practice of writing instructions that reliably get the output you want from an AI tool.
Category: AI Concepts