This world or this life — the world of the living; often contrasted with the afterlife (あの世).
この世に生を受けた意味を考える。
I think about the meaning of being born into this world.
彼女の歌声はこの世のものとは思えない美しさだった。
Her singing voice had a beauty that seemed not of this world.
この世では誰もがいつか死を迎える。
In this world, everyone will one day face death.