A Position applies to an object's absolute location in the game. In Roblox, it can apply to 3D objects or 2D objects. All BaseParts (e.g. bricks, spawns, seats, etc.) uses a Vector3 for the position value, but a CFrame value can also be used for positions (by using the parts CFrame value). And unlike BaseParts, 2D objects, like GUIs, are positioned by UDim2s.