A cosmetic set is several steps of one line packed together, usually in smaller sizes — as a rule a toner, a serum or ampoule, and a cream. The point is not quantity but the whole: instead of guessing which product is missing, you get a routine the maker designed to work together, and can try it from start to finish.
The official description of one such kit puts it plainly: “mini-sized skincare that can be conveniently used during travel or outings”, with an invitation to experience the whole line and “discover your own special skincare routine”. Hence the three usual reasons to buy one: trying a new line before committing to full sizes, a trip that has no room for big bottles — and a gift set, since a whole line is a safer choice than guessing at a single product for someone else’s skin.
Before opening, look at the period after opening — a set usually gets opened all at once. The maker states it for each product: for one Korean skincare set the official data lists 30 months from the production date and 12 months after opening. Minis get used up faster anyway, but that figure tells you how long the routine can wait its turn.
