What is a sitemap? Why do we have to create one for our website?

Sitemaps are the xml or html files which will be submitted to the webmaster tool.
Sitemap gives an idea and guide the robots to crawl your website. And will be indexed.
The Sitemap must:
Begin with an opening <urlset> tag and end with a closing </urlset> tag.
Specify the namespace (protocol standard) within
the <urlset> tag.
Include a <url> entry for each URL, as a parent XML
tag.
Include a <loc> child entry for each <url> parent
tag.
All other tags are optional. Support for these optional
tags may vary among search engines.
Also, all URLs in a Sitemap must be from a single
host, such as Example Domain or
http://
store.example.com.
Optional Tags are,
<lastmod>
The date of last modification of the file. This date
should be in W3C Datetime format. This format
allows you to omit the time portion, if desired, and
use YYYY-MM-DD.
Note that this tag is separate from the If-Modified-
Since (304) header the server can return, and search
engines may use the information from both sources
differently.
<changefreq>
How frequently the page is likely to change. This
value provides general information to search engines
and may not correlate exactly to how often they
crawl the page. Valid values are:
always
hourly
daily
weekly
monthly
yearly
never
The value "always" should be used to describe
documents that change each time they are accessed.
The value "never" should be used to describe archived
URLs.
Please note that the value of this tag is considered a
hint and not a command. Even though search engine
crawlers may consider this information when making
decisions, they may crawl pages marked "hourly" less
frequently than that, and they may crawl pages
marked "yearly" more frequently than that. Crawlers
may periodically crawl pages marked "never" so that
they can handle unexpected changes to those pages.
<priority>
The priority of this URL relative to other URLs on your
site. Valid values range from 0.0 to 1.0. This value
does not affect how your pages are compared to
pages on other sites—it only lets the search engines
know which pages you deem most important for the
crawlers.
The default priority of a page is 0.5.
Please note that the priority you assign to a page is
not likely to influence the position of your URLs in a
search engine's result pages. Search engines may use
this information when selecting between URLs on the
same site, so you can use this tag to increase the
likelihood that your most important pages are present
in a search index.
Also, please note that assigning a high priority to all
of the URLs on your site is not likely to help you.
Since the priority is relative, it is only used to select
between URLs on your site.
The main use of generating the sitemap and
submitting it to the webmaster tool will help the
search engines to crawl your site accordingly and
guide about your site.

Source

a sitemap has the word entails site and map, it's a map that shows  URL complete conical URL set of a website

source: www.enttechub.com

@enttechub wrote:a sitemap has the word entails site and map, it's a map that shows  URL complete conical URL set of a website

source: www.enttechub.com

thanks for reading

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