Increased Attack Speed
From Diablo Wiki
Increased Attack Speed is an Enchantment that can be found on various items and certain runes that can boost the Attack Speed of a certain Weapon.
Like all Good Enchantments, Increased Attack Speed will appear as an enchantment like any other affixes, but determined on the Percent Attack Speed Increased and the Initial Attack Speed of a Weapon, a blue highlight will appear on the weapon with a boosted attack speed, like a fast attack speed of a scepter is boosted to a very fast attack speed by the Increased Attack Speed bonus. the very fast attack speed will appear in a blue highlight over the normal gray color to indicate an increased attack speed.
Increased Attack Speed contributes the most to Paladin's and Barbarians as they both require quick and easy kills to manuever around the map. Increased Attack Speed is not for anyone who doesn't use close range weapons or innefficient close range weapons such as wands. Increased attack speed cannot upgrade a very fast attack speed weapon over it's maximum, so use Increased attack speed enchantments for low attack speed weapons like mauls or giant swords.