PVP stands for player versus player, which basically means that players will fight each other. This is a simple concept, but the execution can vary from game to game. For Dark Souls 3, PVP has two forms. The first form is the mix of PVE and PVP. PVE stands for player versus environment, which basically means that will fight against players AI opponents, like bosses. Sorry I don't think I explain PVE very well. let me try that again just in case what I said be for was not enough. PVE is essentially the "normal" single player experience, where a player fights against computer-controlled enemies. Anyway, back to the first form of PVP. While players are going through the single player part of the game, they can be invaded by another player. Invading another player means that the invading player is entering the invaded players single player experience, which in now no longer a single player experience. The invaded play now has to deal with the invading player and the AI enemies, while the AI enemies will ignore the invading player, which can make dealing with the invading player very difficult. Before we continue, an invaded player is usually referred to as the host, and an invading player is usually referred to as an invader. However, I have heard an invader referred to as a red phantom, but this seems less common. I should mention that there is another way to engage in PVP that is related to the one I just mentioned. When an invader attacks a host, another player called a blue phantom, or just bule, can join to help the host. Another way hosts deal with invaders is to summon other players, themselves. these players are usually called summons, I think. Admittedly, I don't remember if this is the name that they are usually called, but I am fairly certain that this is correct. There is one more PVP method that I will mention. This last method is achieved when the invader becomes a boss. That's right, a player can become a boss. When invading this way, the invader doesn't trigger a blue to appear, but summons can still help the host.
The second form is what I call the PVP Arena, but the game has it labeled Undead Match. I prefer calling it PVP Arena because it's more descriptive. The PVP Arena is where players can fight each other in an arena. Now you know why I think PVP Arena is a more descriptive. These matches can range from 1v1 up to 6v6, I think. I don't remember how high it goes, but 6v6 sounds right. For anyone who doesn't know 1v1 means one player versus one player, and 6v6 means six players versus six players.