Introduction to XPath (XML Path)

An XPath represents a path, and when evaluated on a tree, the result is the node set at the end of any path in the tree. HTML, the formatting language used to configure the data in web pages, aims to create a visually appealing interface. 

In particular, XML Path Language (XPath) provides powerful syntax for handling specific elements of an XML document and, to the same extent, HTML web pages, in a simple way. XPath is defined as a DOM by the World Wide Web Consortium.

There are two ways to use XPath:

• To identify a single item in the document tree
• To address multiple instances of the same item

The main weakness of XPath is its lack of flexibility. Each XPath expression is strictly related to the structure of the web page you are defining.

However, this limitation has been partially reduced since relative road expressions have been added in recent releases. In general, even small changes to the structure of a web page can cause an XPath expression that was defined in an earlier version of the page to not work correctly. In the following screenshot, you can see one XPath rule and its response: