The Concept

XPath provides a convenient, standardized means of drawing a value (or a group of values) from an XML document.  The basic concept is simple—take the concept of a path, as used in mechanisms and Web URLs, and apply it to XML.  This makes sense because, like a file system or the Web, XML documents are hierarchical.  They consist of a group of named entities (primarily elements) that can be nested within one another.  Just like a file or a Web page, the position of any element can be identified using its "path."