About this book

Understanding Large Language Models from the Ground Up is a web-first bilingual open textbook for developers. It begins with observable model behavior, then builds a connected understanding of language modeling, Transformers, modern LLMs, post-training, retrieval and tools, agents, security, and production systems.

The English edition is the technical source of truth. The Chinese edition preserves the meaning of concepts, equations, conclusions, risks, and dependencies while localizing language-specific examples where needed.

Original prose uses CC BY-SA 4.0, and code uses Apache-2.0 by default. Third-party figures, data, and notebooks carry item-level source and license notices.