Artificial General Intelligence (AGI) is built upon many powerful technologies working together rather than a single breakthrough. The Building Blocks of AGI introduces students, educators, and lifelong learners to the essential components that make general intelligence possible. Written in clear, plain English, this book explores the foundations of AGI, including knowledge systems, reasoning, memory, learning, planning, generative AI, agentic AI, autonomy, world models, transfer learning, multimodal intelligence, and ethical decision-making. Through real-world examples and engaging explanations, readers discover how these technologies interact to create increasingly capable intelligent systems. As Book 5 of the IntelliGloss AI Education Series, Module 2: Artificial General Intelligence (AGI), this textbook helps prepare students for a future in which humans and intelligent machines work together to solve complex problems responsibly and creatively.