Right from the start few people will realize they many options they have as to what they can go out and do in order to level-up. Some choose for a more PvP oriented play style to
level up others find more enjoyment 
in a PvE playstyle which also includes the added benefit of spendable Karma Points. Apart from PvE and PvP, players can also Craft, which in contrary to popular belief gives decent amounts of Exp, and each profession can easily level a character 8-10 times once they get their crafting discipline to level cap. Crafting, as in many other games, is gathering materials, (or Mats for short) and then crafting something out of them (pretty self-explanatory). The concept of gathering materials and then using it to create usable creations also exists in Guild Wars 2. Throughout the world of Tyria, there are random spots where you can gather resources: ore, wood, and plants. These are the basic crafting components that you will use to kick start your crafting. Some people prefer to only gather only one or two of those resources because only those two apply to their profession. Before you ask “Does that mean that my guardian can only craft certain items which pertain to that profession?” well no, and let me explain.
The makers of Guild Wars 2 decided to have multiple forms of crafting so that there was a larger diversity in what people would make and possibly sell to others. Each class of crafting has its own types of items it will yield and no two are alike. This being said, you should also know that a single character is only permitted to have 2 types of crafting professions at one time. Although if you want to learn another crafting discipline, than you can pick up that discipline by going to the designated crafting trainer, and initiating conversation. After which, there will be a dialog box where you can trade crafting disciplines. If you do trade a discipline, than the experience of the discipline being traded will not disappear. If you want the traded discipline back, then you can talk with that designated trader and he can give it back to for a small fee.