An XML sitemap is a file of code that lives on your web server and lists all of the relevant URLs that are in the structure of your website. t’s kind of like a “floor plan” for the site, which especially comes in handy whenever the site gets changed. It also helps search engine web crawlers determine the structure of the site so they can crawl it more intelligently. Sitemaps don’t guarantee all links will be crawled, and being crawled does not guarantee indexing. However, a sitemap is still the best insurance for getting a search engine to learn about your entire site. It’s sort of like saying “Hey, Google — check out this fine website.”