"Bursting" is a WLO slang term for a way to get more experience by fighting monsters as a part of a party instead of simply soloing.
You have to catch a pet, of which is usually represented by your level. The pets commonly used are: Pig, Sheep and Cow. You can burst anywhere, but most players prefer to burst in North Island against Jellyfish Monsters, or in South Island against Senior Beetles. You can burst after getting over level 180 or after being Reborn, but you don't get any experience.
The order of moves the common pets use is:
Defend, Defend, Defend, Normal Attack, Normal Attack,
For the characters, each attribute has its own order of moves:
Fire: Slowdown, Poison, Hot Fire Attack, Attack, Attack. (Hot Fire Attack = Fire GS. Recommended attack move for Fires is Fervidity (Dragon Soul Skill) or Hagendis Hit, and for mage, Fire Combo Beating. Any multi-target skills won't work.)
Water: Freeze, Water Shield (on pet), Shrink (Shrink = Water GS), Sleep
Earth: Terrafication, Shield Defense (on pet), Tree Bind, Blockage, Blockage. (Blockage = Earth GS)
Wind: Shield Smash, Speed Up (self), Cord, Coma, Coma.
Teams consist of 3 Fires and 1 Water. Earth and Wind are rarely used.
For Fires to be able to burst, their speed must be lower than that of the cows. As a general rule, go for 0 SPD. Please note that it doesn't necessarily have to be 0, but low enough to be able to combine with your team.