Area in MVC

ASP.NET MVC 2 introduced Area. Area allows us to partition large application into smaller units where each unit contains separate MVC folder structure, same as default MVC folder structure. For example, large enterprise application may have different modules like admin, finance, HR, marketing etc. So an Area can contain separate MVC folder structure for all these modules

The following is adminAreaRegistration class created with admin area.

Area Registration:
public class adminAreaRegistration : AreaRegistration 
{
    public override string AreaName 
    {
        get 
        {
            return "admin";
        }
    }

    public override void RegisterArea(AreaRegistrationContext context) 
    {
        context.MapRoute(
            "admin_default",
            "admin/{controller}/{action}/{id}",
            new { action = "Index", id = UrlParameter.Optional }
        );
    }
}
AreaRegistration class overrides RegisterArea method to map the routes for the area. In the above example, any URL that starts with admin will be handled by the controllers included in the admin folder structure under Area folder. For example, http://localhost/admin/profile will be handled by profile controller included in Areas/admin/controller/ProfileController folder.

Finally, all the area must be registered in Application_Start event in Global.asax.cs as AreaRegistration.RegisterAllAreas();

http://www.tutorialsteacher.com/mvc/area-in-asp.net-mvc