ChatGPT is an artificial intelligence (AI) chatbot developed by OpenAI and released in November 2022. The name "ChatGPT" combines "Chat", referring to its chatbot functionality, and "GPT", which stands for Generative Pre-trained Transformer, a type of large language model (LLM).[2] ChatGPT is built upon OpenAI's foundational GPT models, specifically GPT-3.5 and GPT-4, and has been fine-tuned (an approach to transfer learning) for conversational applications using a combination of supervised and reinforcement learning techniques.