What is a sitemap?
HTML Sitemap and XML Sitemap
A website's map or sitemap is a page on a website that works as an index page of it's contents. It usually shows the main areas of a website and not all of it's pages so that visitors can quickly and directly navigate to the topic they are interested to.
Building a sitemap page is not different from building other pages for your site, it is just a url address that serves an html file (html output).
Similar in concept to html sitemap is the xml sitemap, but which mainly relates to search engines. An xml sitemap is a file in xml format that contains details about all the urls of a website as well as additional information about them. This information are given through specific tags inside the xml file and inform the search engines on the importance of each url, the refresh rate of it's content etc.
The administrator of each website is responsible for the creation of the xml sitemap. Most search engines try to find a file named sitemap.xml inside the root directory of your website, that is in the same folder as your website's homepage. This can be changed by editing the robots.txt file accordingly, where you can declare a different location for the xml sitemap. Usually by placing a sitemap.xml file inside the root folder of your website is enough.
If you want to speed up your website's indexing by google's search engine, there is a way to submit your xml sitemap through google's webmaster tools, if you have enabled this platform for your website. This interface also provides the ability to check the xml file for possible syntax errors for a successful submission and reading by the search engine.