PvP stands for Player Versus Player. It is sometimes a recreational activity, and sometimes used as a means to kill a player for their items. Some servers use mcmmo to enhance PvP. A few basics steps to getting started on a PvP server with McMMO:
Step 1: Weapon choices. There are three staple weapons: The sword, the axe, and the bow. Each have advantages and disadvantages. The sword can block, and has a 'bleed' effect which will drain health from the player a short time after a bleeding hit is done. Axes are potentially the most powerful weapon. If you level it up enough, the axe will do +4 damage more than the vanilla statistics, meaning it is more powerful then a diamond sword. Axes can also do over 20 durability damage to armor per hit at level 1000, meaning even in an equally matched fight, an axe wielder will destroy armor faster then a sword wielder. Finally, the bow can be leveled up to do up to +300% more damage. It also has a daze effect, which will cause a player's head to look somewhere randomly, and a nausea effect to be applied.
Step 2: Enchanting is the next key step to victory. Any weapon you have should have the max level (V) on it. For axes, you will have to use a sharpness books, as regularly enchanting an axe will not give you sharpness. If you are using a sword, Fire Aspect II is a good addition, along with Knockback II to keep your opponent at range, or if you are fighting on hilly terrain. It is recommended all your items are diamond. Your armor should also be protection IV (or projecticle protection IV) depending on who you are battling. *note unbreaking III will not lessen the extra durbaility damage an axe does to armor
Step 3: Potions are another tide-turner for battles. Strength II potions are a must, while others are optional. Leveling your alchemy is recommend, because effects like haste can allow you to swing faster, health boost will allow you to take more hits, and resistance will further your defense/protection.
Step 4: The rest is up to you! Level your McMMO skills, make a base, and fight your enemies! Have fun!