Understanding working and active areas

Working area is used to store files during node creation / editing. When you add a file to a repository it is added in the working area and state. Now when the node is submitted the file is moved to the active area. This allows the admin/system to know which files can be safely deleted if the user never clicks submit.

In addition when a user is editing a node you do not want to overwrite existing files with updated copies until the user clicks submit. So when a file is being updated you upload a working copy and onlyl overwrite the active copy once the user clicks submit.

There is a function which is purge working that walks through the current wokring files and deletes anything that is older than a specfied age (configured through the settings page). This prevents a huge build up of "orphaned" files tieing up precious disk space (as opposed to the stock upload module which relies on PHP sessions ending which may take a long time to happen if you have remember me turned on and the user does not click log out).

Hope this helps the understanding of why an active/and working area is needed.