The Atlas window is a custom window used to display maps for each zone. Unlike the Map window, which only provides access to the maps for the current zone your character is in, the Atlas window provides access to all the maps, regardless of your character's location.
The window will appear when you click on the button labeled "Atlas" in the Main Menu or Command windows of the user interface. The maps contain labels for various regions and points of interest. Some of the maps also show the location of various quest NPCs and encounters.
The maps used in the Map window are "dynamic" and the game client only loads them as you enter into a new zone or area to reduce the amount of system resources used. The maps used with the Atlas however are "static", and the game client loads each of them all at once. Because of this, the Atlas maps can use a significant amount of system resources. To reduce the amount of system resources used by the Atlas, options are available that allow you to disable or set the style of the maps for each realm so only the maps you want to use are loaded.
These options allow you to disable or set the style of the maps loaded with the Atlas window.
These options allow you to conceal, disable, or set the style of the Atlas window itself.