各 (かく) is a prefix that attaches directly to a noun to mean "each," "every," or "respective." It emphasizes that something applies individually to every member of a group, rather than to the group as a whole.
各 is placed directly before a noun with no particle in between.
各 appears frequently with certain nouns, forming set expressions:
各 has a formal or written tone and is commonly found in announcements, instructions, news, and business settings. In casual conversation, speakers are more likely to use それぞれ (each / respectively) or みんな (everyone) instead.
Both 各 and それぞれ express "each" or "respective," but 各 is a prefix attached directly to the noun, while それぞれ functions as an independent word. それぞれ is more flexible and can be used in casual speech as well.