The vocations are similar to professions for your character. You choose it when you reach the level 8 and keep It forever. Selecting one of those vocations directly affects your play style during your adventures, for that reason, you must choose wisely. There are 4 vocations, each of them with different abilities and hunting methods. You can choose between the valiant knights, hawk-eye paladins, dreadful sorcerers and wise druids.
Understanding your advantages and disadvantages on Player Versus Environment and Player Versus Player situations is the key for your success, and the higher is your ability of controlling your vocation, higher are the chances of having your name written on the history of Tibia, and seeing your tales being told among adventurers.
Equip yourself, train and improve your abilities, and be the best warrior that ever stepped the lands of Tibia.