GPT, which stands for Generative Pre-trained Transformer, is a cutting-edge technology that powers many AI chat apps. It is a neural network-based language model that can generate human-like text responses based on given input or prompt. GPT is pre-trained on vast amounts of data to recognize patterns and relationships in language, making it highly effective at generating coherent, relevant, and contextually appropriate responses. With GPT, AI chat apps can provide more natural and engaging conversations that can mimic human behavior and language, making it feel like you're talking to a real person.