I am interested in knowing the precise differences between these three verbs. Wiktionary says this: плыть • (plytʹ) impf (perfective поплы́ть) (concrete impf.), плавать (plávatʹ) (abstract impf.) I am curious about what this means. Is the verb "поплыть" perfective or imperfective? What does it mean for a verb to be "concrete imperfective" as opposed to "concrete perfective"?