Selenium is an industry-standard open-source testing automation framework that uses XPath as a web element locator to automate cross-browser testing of web applications. XPath is a query language used to search for and locate elements in XML and HTML documents, making it the preferred locator when other CSS locators are not found. Selenium WebDriver provides methods to find dynamic web elements using locators like XPath or ID, Class, or other CSS selectors. While XPath can be clumsy to write, brittle, and awkward to reverse engineer, CSS selectors provide bindings that are easier to read and more closely integrated into the browser platform. With Python's high-level programming language environment, Selenium WebDriver provides the functionality needed to run cross-browser tests, allowing developers to use classes or functions to build continuous integration/continuous delivery pipelines. To write a dynamic XPath in Selenium, log into the website, find the XPath extension, and use relative or absolute paths to locate elements based on their attributes, ID, name, tag name, class, or other attribute values.