The guide provides a comprehensive comparison between XPath and CSS selectors, outlining their definitions, functionalities, pros, cons, and use cases. XPath, a query language for navigating XML/HTML documents, offers precise element targeting with a complex syntax and advanced features such as text node selection and backward traversal, but it is less popular and can be slower in browsers. CSS selectors, integral to CSS for targeting HTML elements, are simpler and more intuitive with excellent performance in modern browsers, though they lack advanced functions and cannot traverse upward in the DOM. The guide highlights how each tool performs in web scraping, emphasizing XPath's precision and complexity versus CSS's simplicity and speed, while also addressing challenges related to anti-bot technologies in web scraping.