- Not available on that edition (the reason is in the tooltip)
- Depends on the setting, your class or another addon (details in the tooltip)
What it does
Checks if the game reports that you are outdoors, which is not the same as being outside an instance.
Why you might use it
Check whether the game considers you outdoors, which is what decides whether you can mount or use outdoor-only abilities such as a Druid's Travel Form. Use it so Travel Form or a mount is only suggested where it works, or as a switch condition for a travel or gathering setup outside. Outdoors is not the same as outside an instance; some instances have outdoor areas. See also Instance and Zone.
Example
you are outdoors
Settings
What each setting in the condition editor means, from the game's own help.
Matches when the game reports that you are outdoors. Being outdoors is different from being outside an instance.