ChatGPT is a variant of the GPT (Generative Pre-trained Transformer) language model developed by OpenAI. GPT is a type of artificial intelligence (AI) that is trained to generate human-like text. It does this by learning patterns in large amounts of text data and using this knowledge to generate new text that is similar in style and content to the input it was trained on. In the case of ChatGPT, the model is specifically designed for conversation.