The world or society; the public sphere where people live and interact.
世の中は日々変化している。
The world is changing day by day.
彼は世間の評判を気にしすぎる。
He worries too much about public opinion.
世にも珍しい出来事だった。
It was an event rare in the world.
Life; one's lifetime — used for the span of life (often in contrast like present life/next life).
人はこの世でどのように生きるかが問われる。
It is asked how a person should live in this life.
彼は来世で幸せになりたいと言った。
He said he wants to be happy in the next life.
現世での行いが重要だと説かれることが多い。
It is often taught that one's conduct in the present life is important.
An age, era, period, or generation — a span of time or a cohort of people.
若い世代は環境問題に関心が高い。
The younger generation is highly concerned about environmental issues.
その習慣は江戸の世に始まったと言われている。
It is said that that custom began in the Edo era.
世代交代が徐々に進んでいる。
Generational change is gradually taking place.
A reign or rule — the period during which a sovereign or ruler governs.
その王の治世は平和で豊かだった。
The king's reign was peaceful and prosperous.
古代の王たちは長く世を治めた。
Ancient kings ruled the land for long periods.
治世の終わりに混乱が起きた。
Chaos broke out at the end of the reign.
The times; the spirit or trends of a particular period (e.g., 'the present age').
今の世では情報がすぐに広がる。
In today's world information spreads immediately.
世の流れに逆らうのは難しい。
It's difficult to go against the trends of the times.
このアイデアは今の世に合っている。
This idea fits the current times.
In Buddhism, a 'world' or realm of existence — a technical term used in distinctions like this life and the next.
仏教では現世と来世という二つの世の考え方がある。
In Buddhism there is the concept of two worlds: the present life and the next life.
彼は現世の苦しみから解放されたいと願った。
He wished to be freed from the sufferings of this world (this life).