Difficulty

Difficulty
In survival modes of minecraft, at one point the options for difficulty setting included or include: Peaceful, Easy, Normal, and Hard.

Peaceful Mode: Player regains health over time.No hostile mobs spawn. This is with the exception of the smallest size Slime which will attack but cannot deal damage. The Slime pushes you back a little like a neutral mob, instead of the huge push of a hostile mob when you get hit.

Easy Mode: Hostile mobs spawn. Enemies have less health and deal less damage than on normal difficulty. Creepers will cancel their explosions after moving only a short distance away.

Normal Mode: Hostile mobs spawn. Enemies deal standard damage and have standard health.

Hard Mode: Hostile mobs spawn. Enemies deal much greater damage than in Normal Mode, and Creepers will not cancel their attack unless a big distance is between them and the player, making the explosion much harder to avoid.

Notch has made a tweet on October 23rd where he states that "I'm changing "difficulty" to "realism". Lowest setting = creative. Highest setting = starve"