Language models & chatbots
ChatGPT is OpenAI's chatbot, released in November 2022, that lets people talk to a large language model; GPT stands for Generative Pre-trained Transformer.
ChatGPT was the product that made AI chat mainstream. Language models existed before it, but they were mostly used by researchers and developers. OpenAI put a simple chat window in front of one, tuned it to be helpful and conversational, and it reached a hundred million users within about two months.
The name explains the technology. Generative means it produces new text. Pre-trained means it first learned from a massive pile of text before being adjusted for chat. Transformer is the neural network design underneath. After pretraining, OpenAI used human feedback to teach the model to follow instructions and refuse harmful requests.
ChatGPT is one chatbot among several. As of 2026, Claude, Gemini, Copilot, and others use the same general approach. People sometimes say 'ChatGPT' to mean all AI chat, the way 'Google' can mean search, but it is a specific product from one company.
A student pastes a draft essay into ChatGPT and asks it to point out unclear sentences, then rewrites those parts in their own words.