The "city" is referring to the new Jerusalem, part of the new Heaven and new Earth.
Revelation 21:1-4
"Then I saw “a new heaven and a new earth,”[a] for the first heaven and the first earth had passed away, and there was no longer any sea. 2 I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband. 3 And I heard a loud voice from the throne saying, “Look! God’s dwelling place is now among the people, and he will dwell with them. They will be his people, and God himself will be with them and be their God. 4 ‘He will wipe every tear from their eyes. There will be no more death’[b] or mourning or crying or pain, for the old order of things has passed away.”"
"As the bride of the Lamb and the sons of God come to perfection and the fullness of Christ, the lights and luminaries of the old spiritual heavens truly become darkened, so that the word of the seer of Patmos becomes wondrously fulfilled in us — "And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof."
What city is this ?
The "city" is referring to the new Jerusalem, part of the new Heaven and new Earth.
Revelation 21:1-4 "Then I saw “a new heaven and a new earth,”[a] for the first heaven and the first earth had passed away, and there was no longer any sea. 2 I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband. 3 And I heard a loud voice from the throne saying, “Look! God’s dwelling place is now among the people, and he will dwell with them. They will be his people, and God himself will be with them and be their God. 4 ‘He will wipe every tear from their eyes. There will be no more death’[b] or mourning or crying or pain, for the old order of things has passed away.”"
https://www.biblegateway.com/passage/?search=Revelation+21
oh, ok.
It's the glorious city of God, the people of God are called new Jerusalem, it is the perfected body of Christ, the readied bride of Christ!
All of these things are a Spiritual interpretation of the book of Revelation, it is a gift to the Body of Christ!
"As the bride of the Lamb and the sons of God come to perfection and the fullness of Christ, the lights and luminaries of the old spiritual heavens truly become darkened, so that the word of the seer of Patmos becomes wondrously fulfilled in us — "And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof."