Chapter 5 offers a comprehensive exploration of artificial intelligence (AI) technology. It begins by comparing the cognitive process of humans and AI, revisiting this topic later in the aspect of implementation, using GPT-3 175B model as a case study. The chapter thoroughly details various algorithms, different types of machine learning, and a diverse set of neural networks, including RNN, CNN, VAE, and GAN. It then delves into the transformer architecture and the self-attention mechanism, extending the discussion to transformer-based models such as GPT and BERT. Finally, the chapter addresses the challenges and limitation of AI, covering technical issues, social and ethical concerns, risks and threats, and the need for regulation and governance, concluding with an introduction to the EU’s AI Act (AIA).