Please tell me how i can generate site map of my site and how it help .

You can see it all here:
http://www.microsystools.com/products/sitemap-generator/help/

We must create an site map for every website .  A site map can be a hierarchical list of pages (with links) organized by topic, an organization chart, or an XML document that provides instructions to search engine crawl bots.

There are many free tools available in the internet. However you can use xml-sitemaps which I found better.

Quote from: pihu on November 03, 2016, 04:36:30 AM
Please tell me how i can generate site map of my site and how it help .

Various sitemap generator available.you can use whatever you want visit - https://www.xml-sitemaps.com/