A is for ACL : What does ACL mean ?

Within the contexts of the loose web ACL stands for Access Control Lists. 

Laymans Terms: You know like in facebook when you are logged in you can add things about yourself- well it knows how to store your photos as being yours due to ACL. It restricts your items to your groups you set, you set ACL for yourself.

More Technical: Consider that as a user of a website you may be using the site in different ways. Staff of a web company need to be logged in and verified against ACL's to allow them a set of privileges that customers might not have. For example Staff need to update price lists and customers certainly should not be able to do that.
if you are designing a website and need this kind of control consider very strongly employing the use of pre-written frameworks or CMS. This is not a light an easy subject to just enable on a basic website. The basic site we offer does come with built in ACL to unlimited customisable levels.