When discussing the Greek institution of the Symposium, we often refer to “institutionalized pederasty.” What does this term mean? Why was this practiced by the Greeks?

When discussing the Greek institution of the Symposium, we often refer to “institutionalized pederasty.” What does this term mean? Why was this practiced by the Greeks? Using at least two examples from class discussions, sympotic poetry, or pottery, describe the benefit to society that the Greeks believed arose from this institutionalized pederasty.