Hosting Types – Website Hosting

The Website hosting means that a website is physically located on
the server.

For the website hosting type you can specify:

• Document root. The location of the directory where all files and
  subdirectories of the site will be kept. You can use the default
  directory httpdocs or specify another directory.

• Preferred domain. Typically, any website is available on two
  URLs: with the www prefix (like in www.example.com) and without
  it (like in example.com). We recommend that you always redirect
  visitors to one of these URLs (typically to the non-www version). For
  example, after you set the Preferred domain to the non-www version
  (example.com), site visitors will be redirected to this URL even
  if they specify www.example.com in their browsers.

  Plesk uses the search engine friendly HTTP 301 code for such a
  redirection. This allows preserving search engine rankings of your
  site (preferred domain). If you turn off the redirection by choosing
  None, search engines will treat both URL versions (www and
  non-www) as URLs of different sites. As a result, rankings will be
  split between these URLs.