Explore the architecture and inner workings of GPT algorithms and large language models in this comprehensive conference talk from NDC AI 2025. Begin with fundamental natural language processing concepts including word embedding, vectorization, and tokenization, then witness a hands-on demonstration of training a GPT2 model to generate song lyrics while examining how word sequences are predicted internally. Discover the power, capabilities, and limitations of larger language models like ChatGPT and GPT4, and learn how hyperparameters such as temperature and frequency penalty affect generated output through live demonstrations. Master prompt engineering techniques and understand how Retrieval Augmented Generation (RAG) patterns can create ChatGPT-like experiences using your own textual data, providing practical insights for leveraging GPT algorithms in real-world applications and determining whether your business can benefit from GPT-powered chatbots.