Is the height the same in space?

The height in space can be the same everywhere. I think space is like a square box. Space can be composed of x and y coordinates. I say that the space is square or rectangular, because the space should not be vacuumed to be round or oval. Space is an area covered with gas clouds. Due to the appearance of these gases, we may think differently about the height of space. So the gases may be misleading. We can see that when we pour the liquid paint onto a canvas. The canvas is the same, but the mixed paints create a perception as if there is depth.