The cultures are different because the locations where they exist are differents for example:
Some people live in the desert, they are going to live differently from people living in a jungle.
If you live in the desert you might have never seen a blue flower so you say it's because there is water up there.
But according the context of question I think that there are cultures different only in their details, but there are other that they are so distance because have deep difference of point of view about life for example the oriental world vs the ocidental world.
