A sitemap file like the one shown below contains a list of all the pages on your site and is used by search engines to index your site. Google XML Sitemaps is a free WordPress plugin that creates a sitemap file for your website so your site can be indexed more quickly by search engines.
Going an extra mile, the plugin automatically creates and submits your new sitemap file to the major search engines (Google, Yahoo! and Bing) every time there’s a change (e.g. you publish a blog post).
Lastly, there are many options to configure your sitemap such as the ability to change the ranking of each listing so search engines know, and can present in search results first, the pages you consider most important.