XML Sitemaps
As the name implies, it's a map of your site, telling search engine how to crawl. Sitemaps are the easiest way to communicate with Google. They indicate the URLs that belong to your website and when they update so that Google can easily detect new content and crawl your website more efficiently.
According to Google: You might need a sitemap if:
- Your site is really large. As a result, it's more likely Google web crawlers might overlook crawling some of your new or recently updated pages.
- Your site has a large archive of content pages that are isolated or not well linked to each other. If your site pages don't naturally reference each other, you can list them in a sitemap to ensure that Google doesn't overlook some of your pages.
- Your site is new and has few external links to it. Googlebot and other web crawlers navigate the web by following links from one page to another. As a result, Google might not discover your pages if no other sites link to them.
- Your site has a lot of rich media content (video, images) or is shown in Google News. If provided, Google can take additional information from sitemaps into account for search, where appropriate.
Sitemaps are not necessary, but still strongly recommended for better performance. Always try to make sitemaps dynamic as new content is added.