So they take these special proteins and they take the DNA and they wrap the DNA around the proteins many, many times. So they create coils, and then super coils, and then solenoids and more coils, and eventually they form this extremely condensed and dense version of the DNA we call a chromosome. So, if this is our protein and this is our DNA, we basically take the DNA and we wrap the DNA around the protein many, many, many times. Of course, it's more complicated than this, but you get the point. And once we wrap it around, it's now much smaller than before, and now we can fit it easily into the nucleus of our cell. So that is what a chromosome is.