This is the 2655th most frequent Korean word.
세계를
"세계를" means "the world" (accusative form).
'세계를' is used as the direct object of the verb '여행하다' (to travel), indicating the desire to explore the world.
나는 세계를 여행하고 싶어요.
I want to travel the world.
Here, '세계의' signifies possession, describing the attribute '아름다움' (beauty) belonging to '세계' (the world).
세계의 아름다움은 끝이 없어요.
The beauty of the world is endless.
In this sentence, '세계' refers to a metaphorical or personal world, being the direct object of the verb '창조하다' (to create).