各个 (gè gè) means 'each and every (individual)' and emphasizes the individuality of each member, unlike 每 (měi) which is a general 'every'. As a pronoun it stands alone ('each one'), while 各 (gè) must be followed by a noun. As an adverb it means 'one by one', similar to 分别 (fēn bié) but with a focus on sequential order.