The ancient character “鉴” was initially written as “监.” “监” was first seen in the oracle bone script and later evolved into “鉴” by adding the “金” radical (which signifies metal) during the Spring and Autumn period. It originally meant a tool for reflection, which is similar to a mirror that emerged later. It means reference and can be extended to refer to things serving as reference or evaluation criteria. This character aligns with this book’s goal to become a reference standard and best practice in the industry. Therefore, the book is titled “云鉴” (Cloud Reference).This series consists of four volumes, namely, Cloud Computing in Strategic Perspective, Cloud Computing Technology and Product Research, Green Low-Carbon Digital Infrastructure, and Integration of Cloud Technology and Intelligent Scenarios, covering the strategy planning and execution of cloud computing, the construction and operation of data centers, the applications and practices of cloud computing and related technology, as well as case analyses of digital scenarios. It draws a knowledge graph of cloud technology to broaden readers’ horizons.