XPath is a straightforward declarative language for selecting particular
subsets of nodes from an XML document
A D V E R T I S E M E N T
XPath has a syntax for the selection of nodes, unknown elements, branches,
multiple paths and attributes
XPath queries are written in expressions which can returns doubles or strings
and allow for arithmetic and relational operations on data types
Location paths are an important subset of expressions, they consist of one or
more location step which in turn consists of an axis, a node test, and
(optionally) one or more predicates
XPath also provides a core set of functions for operating on the data types