The term GPT, or "Generative Pre-trained Transformer," refers to a pioneering series of AI language models developed by OpenAI. These models are crafted to simulate human-like text responses based on given prompts, employing a complex understanding of linguistic patterns and contexts. The strength of GPT models lies in their pre-training, which involves learning from a vast compendium of text data, thus enabling them to generate coherent, contextually relevant text sequences.