What is a sitemap regarding Search engine Optimization?

https://www.google.com/webmasters/tools/docs/en/protocol.html

It helps in getting your site spidered.

Sitemap uses a Sitemap Protocol ( an XML file ) that lists URLs for a site
The main tags include –
– Encapsulates the file and references the current protocol standard.
– Parent tag for each URL entry. The remaining tags are children of this tag.
– URL of the page. This URL must begin with the protocol (such as http) and end with a trailing slash, if your web server requires it. This value must be less than 2048 characters.

Someother optional tags are also available to show other info like – last modified, change frequency, priority, etc

sitemap.xml is a file which contains the details of urls, of our website. which are recognised by google, yahoo etc

Example:

http://www.example.com/index.html
2006-07-19
weekly

Like this the file contains all the details about the all our URL’s

u need not worry about it, u can build sitmaps with in seconds at these site by giving the information about your sites, which will build your site maps automatically. They are free

Sandy
http://www.alldebtonline.com

You can watch this free online tutorial
http://www.mr-seo.com/XML-Sitemap-Tutorial.html

From Google, Inc.:

“The Sitemap Protocol allows you to inform search engines about URLs on your websites that are available for crawling. In its simplest form, a Sitemap that uses the Sitemap Protocol is an XML file that lists URLs for a site. The protocol was written to be highly scalable so it can accommodate sites of any size. It also enables webmasters to include additional information about each URL (when it was last updated; how often it changes; how important it is in relation to other URLs in the site) so that search engines can more intelligently crawl the site.

Sitemaps are particularly beneficial when users can’t reach all areas of a website through a browseable interface. (Generally, this is when users are unable to reach certain pages or regions of a site by following links). For example, any site where certain pages are only accessible via a search form would benefit from creating a Sitemap and submitting it to search engines.

This document describes the formats for Sitemap files and also explains where you should post your Sitemap files so that search engines can retrieve them.

Please note that the Sitemap Protocol supplements, but does not replace, the crawl-based mechanisms that search engines already use to discover URLs. By submitting a Sitemap (or Sitemaps) to a search engine, you will help that engine’s crawlers to do a better job of crawling your site.

Using this protocol does not guarantee that your webpages will be included in search indexes. (Note that using this protocol will not influence the way your pages are ranked by Google.)”