Warriors use their strength to beat monsters. The warrior's skill consist on melee.
Warriors are experts on physical attacks and close combat and also on defense and armoury. Warriors are some sort of knight.
Also, warriors are the main blockers of the hunts and quests because of their high close combat skills and high amounts of HP(health points) so if you are planning to make a big hunt or a quest, don't forget to have a good blocker for it!
Another great advantage of the warrior is that they are great to make money (aka: moneymakers) because they can hunt easy creatures without any tipe of waste. If you are planning to get cash or to be a blocker then don't hesitate and become a warrior!