On the CakePHP website it shows that you would create a users table and a groups table for users and user groups using ACL: http://book.cakephp.org/view/1544/Preparing-our-Application
However most other tutorials e.g. NetTuts shows creating three tables (in addition to the users table) to use ACL: http://net.tutsplus.com/tutorials/php/how-to-use-cakephps-access-control-lists/
What is the difference between the two? Thanls