ACL, short for Access Control Lists, controls the rights each user has within your Joomla 2.5 website. These rights include logging in, creating and editing content, and many others.
ACL in Joomla 2.5 is more than just a toggle of who can view what content on the front end of your website. Yes, that is one of the items you can control, but Access Control Lists actually control both front end and administrative back end rights.
What is involved with Joomla 2.5 ACL
Joomla's Access Control Lists are based on the following:
|Users||A user is anyone visiting your Joomla 2.5 website, regardless of whether they are actually logged in or not.
|User Groups||A user group is a literally a group that users can be added to. All users in the group will share the same permissions. If you think about it from the perspective of a school, you could create a new user group for students, a group for teachers, and a group for parents. After assigning users to the user group Students, all students would have the same permissions, however those permissions would differ from what teachers and what parents could do.
|Access Levels||Access levels define who can see content on the front end.
|Core Permissions||Joomla 2.5 Core permissions are the rights you can toggle on and off. For example, a core feature is the ability to log into the front end of the website, or the ability to create new content. Core Permissions are assigned to user groups (referenced above), not to individuals.
In further Joomla 2.5 tutorials, we will provide in more examples on how to use Access Control Lists.
Joomla Community Google+ Hangout #3
June 3rd, 2014
Thank you @RustyJoomla for letting me speak on the Joomla Community Google+ Hangout!