There are two different steps involved in Web Scraping:-
1. Crawling web pages
2. Extracting data from these web pages
Typically, there is a starting URL from where other links are discovered. You can filter these links to restrict the pages that are crawled. XPath is a wise choice for this filtering.
Once you have the HTML content of a page, you can extract any piece of information from it. Once again, XPath comes to the rescue for extracting the data.
On a side note, you can test out our Web Scraper to see how it is done.