The New Jerusalem
This and the following chapter are nice bits of Revelation.
There are two categories of people:
1. Those whose names are in the Book of Life - eternal life.
2. Those whose names are not in the Book of Life - eternal death.
A new heaven and a new earth, new in substance and kind. Nothing in our experience gives us the words to describe heaven.
The New Jerusalem is a symbolic representation of the Bride of Christ, beyond our powers of comprehension this side of eternity.