Dimensions refer to measurable extents of an object or space, typically described in terms of length, width, and height. In mathematics and physics, dimensions help define the size and shape of objects, as well as their position in space. For example, a cube has three dimensions, while a point has zero dimensions, as it has no length, width, or height. In addition to physical dimensions, the concept can also apply to abstract ideas, such as time being considered the fourth dimension. In this context, dimensions help us understand the universe and how different elements interact within it, such as in theory of relativity.