The warrior is the player-character in WarriorJS, which means it's controlled by you. To create a warrior, you'll be guided through a two-step process where you'll determine your warrior's name and the tower you want to climb. Once created, you'll use the warrior to progress through that tower.
The warrior and tower combination is usually referred to as a profile. The number of profiles you can have is unlimited, but you can't use the same warrior/tower combination twice.
A warrior has the same attributes that any other unit. It also has abilities and can be under effects.