Perhaps you've heard of a sitemap before, but have you ever seen one or know what they are used for? For the casual internet surfer, they aren't very important. In fact, it would be argued they don't matter at all. However, sitemaps are quite important in terms of SEO.
What Does a Sitemap Do?
A sitemap provides clues to site crawlers about a website. The information provided about a give page can include: the URL, how important the page is (to create a hierarchy), update frequency, and date modified.
All of this information is useful for a crawler to know how and when to crawl a website.
So what's it look like? See for yourself!
Usually, sitemaps don't look this good, but yours truly has made it so and StoragePug sitemap looks nice. However, a web crawler doesn't care about this. Either way, here is an example of what an un-styled sitemap looks like.
For complex and/or large websites, sitemaps can link to other sitemaps to create a hierarchy. For example, Public Storage has a huge website, so their sitemap links to other sitemaps.
In summary, a sitemap is exactly what it sounds like - a map of a website!