Capture the Wool, commonly known as CTW, is a gamemode where the aim is to take your wool from the enemy's side, and return it to your base. The wool must be placed on the wool monument made especially for that wool. When all wools have been captured (and all other possible objectives finished), the match is complete.
Wool rooms are special areas typically located on the far ends of the map that house the wool. There are many maps with more than one wool room, for different wools. Special equipment is typically stored in these to aid in the voyage back to spawn. The wool rooms are inaccessible by the team that holds them, meaning that they serve as a safe zone until one exits the room. Wool rooms are often indicated by a marker such as a beacon or a large floating object or letter. The room itself can have anywhere from one to three floors, and vary in shape and size. The wools are usually stored in a chest or can be obtained by a spawner. Wool rooms are usually located at the end of long paths. These paths, typically have one or more walls of bedrock to disallow tunneling, but it is quite common to see players create even more challenging defences.
Wool monuments are a singular, one block space where the wools are to be placed. They are often located within the spawn, or nearby. This one space is reserved only for it's respective wool, and no other blocks can be placed in it. Once a wool is placed on the monument, it is impossible to reverse the action, and the wool cannot be broken, even if the enemy team manages to reach it.