Diablo III- Skills Article LXV: The Monk, Core Article

The Monk is the second of the melee-centric classes in Diablo III, and has the same ‘I’m a tank’ benefit as the Barbarian- a 30% reduction to all incoming damage.  Unlike the Barbarian, rather than having a lot of Armor from a high Strength score, it dodges a lot of hits thanks to a Dexterity focus.  Also unlike the Barbarian, it regularly competes with a ranged class for gear- both it and the Demon Hunter will want to wear a lot of the same armor, rings, and necklaces.  Perhaps amusingly, the Monk actually focuses less on mobility than the Barbarian, and above that, relies equally heavily on a more modest number of more powerful hits- though several Monk skills get in more hits per use, the Barbarian skills are often faster to attack with.

While Barbarians are melee heavies with a lot of side skills for striking at range and a small cluster of team-oriented skills, the Monk is heavily invested in team-benefitting skills and has relatively little in ranged options, instead boasting more than a few ways to close the gap and get into melee with what they want to be hitting.  The Monk also has more access to area and multiple-target attacks than the Barbarian does, using their skill slots for two party-friendly options (that can also be used by the solitary Monk) and two additional forms of offense.

This effectively makes the Monk a more stable damage dealing class than the Barbarian, since they have two skill slots essentially reserved for occasional defensive use and will be switching up their attacks less often.  Barbarians -can- dedicate two slots to non-attack capabilities, but they rarely have a good reason to push that much in, and most of their effects of the non-direct-offense sort are intended to boost the Barbarian more than anything else.  The Monk ,on the other hand, is a natural ‘team player’, as all their options for two of their skill slots benefit allies just as much as, if not more than, the Monk themself.

This means that while the Barbarian keeps the danger away from teammates by being a big threat in the enemy’s face and making themself more powerful, the Monk keeps the danger away from teammates by making the other party members better - buffing them in one way or another, or even outright healing them with the base form of a skill.

The real upshot of this is that Barbarians and Monks play differently, and it’s not just a matter of speed versus might, as is so common in other games.  This is one of the areas where it’s clear a lot of thought and work went into the game- the melee classes play differently but their differences are not so easy to qualify, and require actual playtime to get a proper handle on.