The community is very different from our own in many ways. We do not know the exact location or time period, although since it is dystopian/fantasy fiction we usually think of it as being set some time in the future. When the book opens, it is some time in the fall as Jonas is looking ahead to December and the Ceremony of Twelve. The story takes place in a little over a year. The following December, Jonas and Gabriel escape the community on the day of the Ceremony of Twelve.
The actual community is not described in much detail. It is composed of a tight collection of houses and communal buildings, surrounded by agricultural fields and then open land. We do know there is a river near the community, and that there are other neighboring communities not too far away. The community is flat.
At some distance from the community is a place called Elsewhere, where the word is similar to ours. Elsewhere might be an afterlife, like Heaven, or a real place. In between the community and elsewhere there are hills, other rivers, trees and woods.