Markets can behave in ways that are either competitive (my tomatoes are better than your tomatoes) or co-operative (my tomatoes are a perfect complement to your cheese). And sometimes they morph from one mode into the other.
Outside an individual company, competition is favoured over cooperation, except when companies work together on e.g. supply chains.
It's possible that companies (knowingly or unwittingly) co-operate under some circumstances, though - even if competition is generally the {expected/favoured} model.