XMLXPath

XMLXPath, often referred to as XPath, is a query language used for selecting nodes from an XML document. It was developed by the World Wide Web Consortium (W3C) and is a crucial component of technologies like XSLT, XQuery, and the DOM. XPath treats an XML document as a tree of nodes, including element nodes, attribute nodes, text nodes, and more. It provides a path expression syntax to navigate this tree structure and select specific nodes or sets of nodes.

The fundamental concept in XPath is the path expression, which specifies a sequence of steps. Each step selects a set of nodes relative to the current node. Axes, such as child, parent, ancestor, and descendant, define the relationship between the current node and the nodes to be selected. Predicates, enclosed in square brackets, can be used to filter the selected nodes based on conditions. For instance, an XPath expression like /root/element[@attribute='value'] would select all 'element' nodes that are children of the 'root' element and have an attribute named 'attribute' with the value 'value'. XPath expressions are designed to be concise and powerful, enabling efficient retrieval of data from XML documents.