Settle for an approximate word meaning

Sometimes context will help to infer the approximate meaning of an unfamiliar word. Consider the sentence Ученик пошел в магазин и купил шариковую ручку (The students went to the store and bought a ______ pen). You might infer that the adjective шариковую means some kind of a pen. What kinds of pens are there? Or does it really matter in this case?