Yes, order is important here, but you need to consider it correctly. There are 8C4 ways of choosing four balls. Once those four balls are chosen, there are 4! ways to put them in order. That is, there are
4!*8C4 (which is equal to 8P4)
ways of both choosing four balls *and* putting them in order. *But* only one of these 4! orders is increasing; the remaining 23 orders we might choose are not increasing. There is 8C4 ways of choosing four balls, and only 1 way to put them in increasing order, so the answer, as pointed out above, is 8C4.
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