Generative Pre-trained Transformer (GPT) is a series of advanced language models developed by OpenAI, utilizing deep learning and the Transformer architecture to generate human-like text. Starting with GPT-1 in 2018 and evolving through significant advancements like the massive GPT-3 and the multimodal GPT-4 and GPT-4o, these models have demonstrated remarkable capabilities in text generation, question answering, translation, and even code creation. Trained on vast datasets, GPT models learn language patterns and can be fine-tuned for specific tasks, making them versatile tools across numerous applications, from content creation and customer service to education and healthcare. While possessing impressive abilities, GPT models also have limitations, including potential inaccuracies, biases, and challenges with reasoning and long-form content, highlighting the ongoing need for refinement and responsible use.