"All the world's a stage,
And all the men and women merely players."
Here, 'All the world's a stage' is an example of -

All the world's a stage,
And all the men and women merely players.
They have their exits and their entrances.

- 'All the world's a stage' is an example of Metaphor.
- The 'world' has been compared to a 'stage' to suggest short life on earth.
- 'Entrances' and 'exits' are also metaphors that imply birth and death respectively.

Source: An ABC of english Literature, Dr. M Mofizur Rahman