In the Miva admin, there are two kinds of sitemaps: HTML sitemaps and XML sitemaps. They are similar in nature, but function differently.
HTML Sitemaps: An HTML sitemap is for your customers and gives them a general overview of your store. Customers can see the HTML sitemap for your store by clicking the Sitemap link, usually found in the bottom navigation section of your store’s website. Your HTML sitemap can be customized by editing the SMAP page.
XML Sitemaps: An XML sitemap also provides a general overview of your store pages, but it is designed to be indexed by search engines, like Google. When your XML sitemap is indexed by a search engine, it increases the odds that a customer will see links to your store when they run a search through that search engine.