This is the 723rd most frequent Korean word.
세상을
"세상을" means "the world" (object form).
In this sentence, '세상을' refers to 'the world' as the object of the verb, indicating the realm or place to be traveled.
그는 세상을 여행하고 싶어 합니다.
He wants to travel the world.
Here, '세상을' is used to denote 'the world' as the object, implying the target of the action (making better).
세상을 더 나은 곳으로 만들기 위해 노력하세요.
Strive to make the world a better place.
In this case, '세상을' points to 'the world' as the object of the verb, symbolizing the entity being changed.