Enhancement Bonus

An enhancement bonus is a bonus granted to a character by a magic item. Enhancement bonuses can be applied to almost any stat, skill, or score of a character, as the effects from magic items are diverse and powerful. Enhancement bonuses to the same element of the character do not stack, but enhancement bonuses to different elements can be applied simultaneously.

For example, you can have an item which grants an enhancement bonus of +4 to your Strength score, and a different item that grants a +2 enhancement bonus to your Survival skill checks. Both of these bonuses apply, since they are affecting different elements of the character. However, two items which both grant an enhancement bonus to a character's Strength score would not stack; instead, only the highest available bonus would be applied.