Instead of hunting all over Firefox to change various website permissions, the Permissions Manager now collects them all in one place. You can customize permissions for individual sites or set the default permissions for all sites. This article will get you started.
To open the Permissions Manager, just type the words about:permissions into the location bar as if it were a website and press Enter. The current tab will be replaced by the Permissions Manager.
On the left hand side you'll see a search bar with a list of all the websites you've been to below it. The right hand side lists the various website permissions that Firefox stores.
To work with a single website you have to select it from the list on the left side. You can quickly narrow down that long list by typing part of the site's address in the search box. Once you've selected a site, you can manage its permissions with the settings on the right.
To manage the default permissions for all websites select All Sites from the top of the list of websites. Now the settings on the right represent the default permissions for all websites.
The Permissions Manager gives you easy access to the following: