Release is considered a terrible punishment for an adult, sad for a baby, and worthy of celebration for an old person.
The first time we learn about release, they are talking about the pilot that accidentally flew a plane over the community. There was an announcement saying he would be released. Jonas reflects on that.
For a contributing citizen to be released from the community was a final decision, a terrible punishment, an overwhelming statement of failure. (ch 1, p. 2)
At this point, we can only guess that release might mean permanent expulsion or even death. We are told that the only time release is not a punishment is when it is a Newchild (a newborn baby), and the elderly. It seems they release the elderly before they get too old and might be in pain. Newchildren that don’t grow fast enough are released.
All of these releases are in an effort to make the community perfect. Anyone who doesn’t comply, does not look like the others, or does not act like the others, is a goner. We simply can’t keep those people around. We need to enforce Sameness at all costs, or people might feel uncomfortable.
Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book). Houghton Mifflin Harcourt. Kindle Edition.