Google XML Sitemaps
Google Sitemaps are a feature that informs the Google algorithm in your site's architecture. They make it easy for Google, Yahoo, Bing and other search engines to crawl and index the pages on your website. To put it simply, a sitemap is a map of all your site's pages and posts. In the absence of a sitemap, your website will not be properly indexed.
The programming language used to write sitemaps is known as XML (extensible markup language). This makes it difficult for people who do not have programming knowledge to write sitemaps for their website. Fortunately, the Google XML Sitemaps WordPress plugin makes it easy to generate a sitemap for your website. It takes the pain out of having to manually write an XML file.
How to use it
Search for the "Google XML Sitemaps" from the plugin page in your WordPress dashboard. Activate the plugin and navigate to the settings page. The settings may look a bit intimidating at first but there is really nothing to it once you understand what you need to do. The following are some of the configurations you will need to make:
Build it the first time – the first thing you need to do is to build your sitemap the first time.
Customization of basic options – you may want to make a few changes in the basic options dialog box. Most notably, you will need to get a Yahoo application ID in order to notify Yahoo about updates to your blog.
Additional pages – in case you want to include sub-pages and sub-directories of your blog on the sitemap, you can make use of this section to add the additional URL's
Sitemap content – here you can specify the sections of your website you want included in your website
Excluded items – specify the items you want excluded from the sitemap in this section
Frequencies and priorities – in these sections you need to specify how often you want search engines to crawl your pages and the priority of each page in the index. The default settings are usually good but you may want to make some customizations based on your requirements.
The final thing you need to do to get the most out of your sitemap is to create an account at Google's webmaster tools and enter the sitemap URL. The URL will always be in the format yourwebsite.com/sitemap.xml. Once your sitemap is up and running, it does not matter how many changes you make on your website, search engines will always be able to crawl your website and index your pages with ease.