Search Engines will typically crawl your site for pages on a daily/weekly/monthly basis.  It all depends on how popular your site is and how often you refresh and/or update your content.

A XML sitemap is a way for you to submit to search engines a list of all your site pages so the search engines will have easier time crawling and cataloging your site.

This plugin generates an XML sitemap based on the configurations you give it. Usually all the SEO plugins come with predefined values that match well with most sites and there is no need to change them.

In the case that you would like to change the setting, you can do it from the link “DDsiteMapGen” located under the Settings tab.

As with most wordpress plugins the fields are clearly marked and are mostly self-explanatory and where required there is helper text next to or below the field in question.