Toothpaste manufacturers understand that consumers have different needs when it comes to toothpaste (i. e., teeth whitening, sensitive teeth, breath freshening, and tartar control). knowing that, they have divided the market based on these various needs and developed toothpaste to accommodate each group. by doing so, these toothpaste manufacturers are involved in

I would say this sounds like a kind of niche marketing whereby different varieties of the same product are tailored to the individual needs/likes of the consumers in order to satisfy those particular needs and thus have successful sales. But while this may be niches, also they are all related to the teeth cleaning products so are segments of that single market, all related to it at least I would say I believe this would be correct.