Introduction: What Is a Knowledge Graph?

Since its inception by Google, Knowledge Graph has become a term that is recently ubiquitously used yet does not have a well-established definition. This section attempts to derive a definition for Knowledge Graphs by compiling existing definitions made in the literature and considering the distinctive characteristics of previous efforts for tackling the data integration challenge we are facing today. Our attempt to make a conceptual definition is complemented with an empirical survey of existing Knowledge Graphs. This section lays the foundation for the remainder of the book, as it provides a common understanding on certain concepts and motivation to build Knowledge Graphs in the first place.