GPT refers to a family of large language models developed by OpenAI, standing for Generative Pre-trained Transformer. These are autoregressive language models based on the Transformer architecture, which are pre-trained on massive corpora of text using unsupervised objectives (like predicting the next word). The “pre-trained” part means they capture a lot of general language understanding. GPT models (GPT-1, GPT-2, GPT-3, etc.) have increasingly large numbers of parameters and can generate coherent and contextually relevant text given a prompt. After pre-training, they can be fine-tuned for specific tasks (though GPT-3 is often used directly via prompting due to its size and generality). The architecture uses self-attention mechanisms to handle long-range dependencies in text effectively. GPT models have demonstrated impressive capabilities in generating human-like text, answering questions, and performing various NLP tasks, influencing a surge in research and applications in NLP.