In the traditional stove/oven set up, the two are combined in one appliance. As kitchens grew and people wanted larger ovens, or two (!), separate wall ovens became popular. Often you'll see the double oven set up with the microwave stacked in there too.
As "classic" or "retro" have become more popular, there has also been a return to the combined range and oven (or two!).
If you were building new, which would you opt for?