What is “XML sitemap”?
By placing a formatted xml file with site map on your webserver, you enable Search Engine crawlers (like Google) to find out what pages are present and which have recently changed, and to crawl your site accordingly.
What is “Change frequency”?
This value indicates how frequently the content at a particular URL is likely to change.
What is “Last Modified”?
The time the URL was last modified. This information allows crawlers to avoid recrawling documents that haven’t changed.
You can let the generator set this field from your server’s response headers or to specify your own date and time.
What is “Priority”?
The priority of a particular URL relative to other pages on the same site. The value for this tag is a number between 0.0 and 1.0, where 0.0 identifies the lowest priority page(s) on your site and 1.0 identifies the highest priority page(s) on your site.
The default priority of a page is 0.5.