Sites is a feature of Force.com that enables public access to your Visualforce pages. A site is a collection of ordinary Visualforce pages and access control settings assigned to a unique base URL. You can define one or many sites within a Force.com organization. Sites can be individually brought up or down by your organization’s system administrator.
This section divides the discussion of Force.com Sites into four parts, summarized next:
1. Enabling and creating a site—Turn on the Force.com Sites feature and create your first site.
2. Security configuration—Configure the privileges granted to the anonymous user of your site.
3. Adding pages to a site—Select Visualforce pages that are accessible within a site. ...