Search engine indexing

[nick_westlife]

The search engine will index the pages in your web automatically. You need not do anything for that.

Then why people say that we should submit our site to Google and add sitemap to index our page in Google search?

Google puts your sites into their database when the google bots visits your site. Visiting of google bots may take 1 or 2 months so Before google bots visits our site what the members do is submit their site to google in order that google will see those sites and bots will visit it soon.