The torso is found in almost all humanoids. It is a 2 x 2 x 1 part. A torso is important to any ROBLOXian or Humanoid, because without it, the arms, legs, and head would not be attached to anything. Losing your torso will cause you to lose all your health. In scripting, it is referred to as the "HumanoidRootPart".
The torso is the part under the head, above the legs, and between the arms. It is important to the character, once again, because it is connected to the arms, legs, and head. If you lose it, your health would automatically go to 0, and you would die. When you wear a T-Shirt or a Shirt, it will go over the color of the torso. Transparent areas will reveal the color of your torso.