XPath primarily handles the nodes of XML 1.0 or XML 1.1 trees. It is used to represent the hierarchical structure of an XML document. XPath uses non-XML syntax and works on the logical structure of XML documents. This structure is also known as the data model. XPath is designed to be used embedded into a programming language. It has a natural subset that can be used for mapping.
A regular expression, regex or regexp, represents a search model used in computer science. Regex emerged as a result of the work of the American mathematician Stephen Cole Kleene in the 1950s. It is also being used with Unix text-processing programs. There are different forms of syntax for writing regular expressions: the POSIX standard and Perl syntax. A regular expression in search engines is used in search and replace operations and lexical analysis...