WebDriver XPath is an important concept to understand. It allows someone to use an alternative way of finding an element or object on a webpage. Xpath provides similar solutions to findelements however focuses more on the actual content of html tags.
WebDriver XPath Video Tutorial
It is also important to note that Xpath is known to be very unstable for tests. A simple or single change to the structure of a html page may very quickly break your tests. This is because the Xpath path may now no longer be valid for the element which you intend to interact with.