Environments refer to Development, Alpha, Beta, Staging, Production, etc..
This is incredibly useful if having multiple environments for each of the sites, and forgetting which version of the site currently viewing.
This module can help avoid making configuration changes to a live server by mistake, by adding a coloured strip to the side of the site, clearly marking each version of the site.
The Environment Indicator settings page allows to modify some elements of the indicator's behaviour and appearance.
The Environment Indicator's visibility depends upon the permissions of the viewer (access environment indicator).
Unpack in your modules folder (usually '/sites/all/modules/')
Enable under Administer > Site Building > Modules
· Drupal 6.x