The first step in security is always authentication: the process of verifying

who the user is. With Symfony, authentication can be done in any way - via

a form login, basic HTTP Authentication, or even via Facebook.

Once the user has been authenticated, authorization begins. Authorization

provides a standard and powerful way to decide if a user can access any resource

(a URL, a model object, a method call, ...). This works by assigning specific

roles to each user, and then requiring different roles for different resources.