Do you know? - Rest System

The Rest State modifier gives players a time-limited bonus to combat experience. Rest State is gradually earned while you are logged out of the game, or when your character is located in a city or inn

Rest State: //EDITED
- Rest State allow 200% experience from killing monster
- Every 8 hours of Rest = 1 bubble in experience bar.
- Maximum of Rest bonus is 30 bubble = 1.5 level
- Rest experience are in blue while normal is purple.
- Rest bonus only apply to killing mobs, not from quest reward or map exploration.

For Detailed Info Visit: http://www.worldofwarcraft.com/info/basics/resting.html