Reincarnation? [ Tenten is able to piece out just what he means in that context. Aang's explanation starts to jog her own memory until she comes up with her own analogy. The tailed beasts. ]

So, it's like the tailed beasts in my home. You're passed from person to person. Whenever a jinchuuriki, or someone that holds a tailed beast, dies or is reaching old age, they pass it onto another person who hones their skills with it. The tailed beast has its own soul while you guys have your separate soul. We don't have anything that makes you able to go and talk to past Jinchuurikis though. Or, at least, as far as I'm aware, there isn't any method.