A sitemap is quite simply the map of all the publicly accessible webpages on a given website. Sitemaps are usually organised in hierarchical format, as this is the best way to indicate to Google’s web crawlers which pages relate to which other pages – and which are more important than others.
In order to implement a sitemap on a website, a webmaster must create a file and place it in the website’s root directory. The file should be in XML format in order for web crawlers to easily access and read the file and understand which webpages exist down which hierarchical bonds.
