The ASP.NET Identity system, new in Visual Studio 2013, is designed to replace the previous ASP.NET Membership and Simple Membership systems. It includes profile support, OAuth integration, works with OWIN, and is included with the ASP.NET templates shipped with Visual Studio 2013.
My experience with it is that it is simpler to use yet provides more options and easier extensibility.
ASP.NET Identity can be used with all of the ASP.NET frameworks, such as ASP.NET MVC, Web Forms, Web Pages, Web API, and SignalR.
Check out it’s claims based authentication. It gives you the ability to use more than just roles to grant access/permission to a user.