Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 66:1-17, 21-24.
In the end, Yahweh will enact his perfect justice. This is the true hope of this world. The new heaven and the new earth are an important part of this. In the end, this will be the perfect creation of Yahweh and will last forever. (See: [[rc://en/tw/dict/bible/kt/justice]], [[rc://en/tw/dict/bible/kt/hope]] and [[rc://en/tw/dict/bible/kt/eternity]])