ChatGPT is a variant of GPT (short for "Generative Pre-trained Transformer") that is specifically designed for generating text in a chat-like style. It is trained on a large dataset of conversational exchanges and is able to generate text that is appropriate for use in chatbots and other conversations. GPT, on the other hand, is a large language model developed by OpenAI, a Silicon Valley-based startup founded in December 2015 by Sam Altman, Elon Musk, Peter Thiel, Reid Hoffman, and Jessica Livingston, with $1Bn in funding.