XPath is a language offering the possibility to navigate through elements and attributes, and find information in an XML document. XPath is developed by the World Wide Web Consortium (W3C) and is ranked as an important element in the W3C's XSLT standard.

However, it should be noted here that XPath is not complete in itself, but rather designed to be embedded in a host language. For example, with XPath, XSLT follows the simple tree-structured data model of XML documents and finds the necessary elements and attributes for transformation.

XPath was designed to be used not only by XSLT, but also by others XML parsing softwares such as XPointer or XQuery.

The two main tasks of XPath is to locate and retrieve nodes or elements in a XML tree and to perform operations over data. That can be operations over numerical data, for example count, add or round; or operations over strings, for example return the part of a (sub-)string, or return the length of a string etc.

There are two versions of XPath in use today: XPath 1.0 and XPath 2.0. The XPath 2.0 is designed to be used in XSLT 2.0 and XPath 1.0 in XSLT 1.0. The important differences between the two versions is, that XPath 2.0 supports more expressions and types, has new data model, new operators and more functions.