In MVC4 WebSercurity is very simpler and manageable way of providing log-in registration service to the users. It is simpler than membership provider and reduced database tables and in fact it is built on the top of membership provider. Provides more features than Membership provider, just need to user WebSecurity class which has following methods:
First method in the list is very important, because it creates websecurity's required tables in your database, all methods are link with documentation where they are explained very well. WebSecurity is by default provided with MVC4 project template.