Books always refer to human DNA as a unique molecule, and two different humans generally have different DNA molecules. But how many different types of DNA molecule does a person have?
In order to make this more understandable, let's give a physical/mathematical definition of molecule equivalence classes. Two molecules are in the same equivalence class if they have the same atoms in the same relative position to each other. And we say these two molecules are equivalent. In other word they are chemical clones of each other, like two $H_2O$ molecules are equivalent.
My question is this: how many equivalence classes of DNA does one human have (before being damaged or mutated)? 1, 23, 46, 92 or another number? Does a human have 46 or 92 different kinds of DNA molecules or just one that wraps differently to give different chromosomes? The same question could be given for a whole person or a single human cell.
Yes, I have looked on the internet and even asked a biologist. It seems the answers are always confusing to me because of the definition of the terms. What biologists seem to call "the DNA molecule" seems to be an ensemble of different equivalence classes of molecules, and I am finding this confusing.