Competence bonus

From DDO wiki

A competence bonus is a type of bonus given to skills, which is given by most magic items found in Stormreach.

A competence bonus (or penalty) affects a character's performance of a particular task, as in the case of the bardic ability to inspire competence.

Such a bonus may apply on attack rolls, saving throws, skill checks, caster level checks, or any other checks to which a bonus relating to level or skill ranks would normally apply. It does not apply on ability checks, damage rolls or other rolls that aren't related to a character's level or skill rank. Multiple competence bonuses don't stack, only the highest bonus applies.

Other types of bonus to skills are enhancement bonuses and morale bonuses.