According to W3C, the Semantic Web is a “web of data” that enables machines to understand the meaning (semantics) of the data/information presented in the World Wide Web. It extends the network of hyperlinked human-readable web pages by inserting machine-readable metadata about pages and how they are related to each other, enabling automated agents to access the Web more intelligently and perform tasks on behalf of users. With more research about semantic web in research organizations and in industry, the Semantic Web is quickly emerging as a well-recognized and important area of computer science. This book, Introduction to the Semantic Web: Concepts, Technologies and Applications, provides a quick review and discussion on some key problems in the semantic web. Specifically, this book focuses on the following emerging areas/questions: how we can make use of the semantic web and its technologies to improve searching (Chapter 1 to Chapter 3), what is the relationship between web services and the semantic web (Chapter 4 and Chapter 5), how we can develop social semantic web via social tagging (Chapter 6), how we can improve work collaboration and resources allocation by using semantic web (Chapter 7 and Chapter 9), what are the major privacy concerns in the semantic web (Chapter 10 and Chapter 11), and how to semantic web via data mining, Semantic Web Constraint Language and Web Ontology Language (Chapter 12 to Chapter 14).