- 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 character class of the unit specified is the class you choose.
Why you might use it
Checks a unit's character class. It is mostly useful in PvP or on your target's target, for example choosing Fear or Polymorph against casters and slows or disarms against a Warrior or Rogue, or picking the right buff for a friendly target. On Retail and WoW Forever the game hides the class of NPCs outside your group, so against NPCs the condition is unavailable there, while players and group members still read. See also Class In Group.
Example
your target's class is Warrior
Settings
What each setting in the condition editor means, from the game's own help.
Unit - The unit this condition uses as the target of comparison.
Class - The character class of Unit.