[ASK] difference http://www.(domain) and http://(domain)

can anyone tell me the difference between those 2
does it affect your web server if you use or not use the www?

Thanks

 

Not have the same effect. whether or not to use www

 

All that's important is you choose one form and stick to it.

You should also redirect the other form to the form you choose so that visitors can find your site if they include www or not. The redirect also stops search engines seeing your site on to different URLs.