In topology, different shapes are distinguished by abrupt transitions. Consider the holes found in some breads. A loaf of bread has no holes in it. To create a bagel shape, one needs to cut out a hole. A pretzel with two holes can be made from a looped cord of bread. But to morph from the bread loaf shape into a bagel or looped pretzel, a baker needs to introduce a hole or two. That makes each shape, from a topological point of view, quite different.