XML documents are E xtensible. XML Elements have Relationships Elements are related as parents and children. To understand XML terminology, you have to know how relationships between XML elements are named, and how element content is described. Book is the root element . Title and chapter are child elements of book.
Book is the parent element of both title and chapter.
Elements have Content Elements can have different content types. An element can have element content, mixed content, simple content, or empty content. An element can also have attributes . In the example above, book has element content , because it contains other elements. Chapter has mixed content because it contains both text and other elements.