A `sitemap.xml` file is an XML file that lists the URLs for a site along with additional metadata about each URL. This helps search engines like Google to crawl the site more effectively. Here’s a simple example of what a `sitemap.xml` might look like:
```xml
http://www.example.com/
2023-10-01
daily
1.0
http://www.example.com/about
2023-10-01
monthly
0.8
http://www.example.com/contact
2023-10-01
yearly
0.5
```
Here’s a breakdown of the elements used:
- <urlset>: The root element that contains all URL entries.
- <url>: Represents a single URL entry.
- <loc>: The location of the URL.
- <lastmod>: The last modification date of the URL.
- <changefreq>: How frequently the content at the URL is expected to change.
- <priority>: The priority of the URL relative to other URLs on the site.
Using a `sitemap.xml` helps improve a site's SEO by providing search engines with structured data about the site's pages.