All the worlds's is a stage (poem) with reference to context and explanaition

                      All the world’s a stage(poem)

And all the men and women merely players

They have their exits and their entrances

And one man in his time

 plays many parts

His acts being seven ages

 At first the infant,

Mewling and puking in the nurse’s arms;

And then the whining school-boy, 

with his satchel

And shining morning face, 

creeping like snail

Unwillingly to school.

 And then the lover,

Sighing like furnace,

with a woeful ballad

Made to his mistress’ eyebrow

Then a soldier

Full of strange oaths

and bearded like the pard

Jealous in honour

sudden and quick in quarrel

Seeking the bubble reputation

Even in the cannon’s mouth

And then the justice

In fair round belly with good capon lin’d

With eyes severe and beard of formal cut

Full of wise saws and modern instances

And so he plays his part.

The sixth age shifts

Into the lean and slipper’d pantaloon

With spectacles on nose and pouch on side

His youthful hose

well sav’d, a world too wide

For his shrunk shank

 and his big manly voice

Turning again toward childish treble, pipes;

And whistles in his sound.

 Last scene of all

That ends this strange eventful history

Is second childishness and mere oblivion

Sans teeth, sans eyes, sans taste, sans everything

Reference
This sonnet of Shakespeare is from his  play “As You Like It”.
context:
This poem describes various stages of human life. Life has been compared to a play  played by  men and women on the stage of the world. His seven stages of life are the seven acts of a play. This shows Shakespeare’s deep knowledge  of human life.
Shakespeare ,the greatest dramatist and poet sees this world from the eye of an actor and thinks that this world is like the stage of a theatre.All the men and women are the actors of the stage.According to Shakespeare ,they perform acting on the stage in seven different parts or roles .In other words ,he divided the human life into seven parts.
First stanza

And all the men and women merely players-

They have their exits and their entrances-

And one man in his time-

 plays many parts-

His acts being seven ages-

Explanation:
In these lines of poem  the poet compares this world to a stage. All men and women are only actors and actresses on the stage of  world. All these people have different routes to enter this stage and have different exits to go out. They enter this stage when they are born and leave  when they die. Every person, during his life  plays many parts. These parts are called seven ages. These ages are actually like acts of a play.
Second stage

And then the whining school-boy

with his satchel-

And shining morning face

creeping like snail,

Unwillingly to school
The second stage is his boy-hood. This is boy's school going period. It is the time when he complains all the time. His face shines like the bright and cold fresh morning. He carries his school bag and unwillingly goes to school slowly at the speed of an insect.

Third stage

 And then the lover,

Sighing like furnace,

with a woeful ballad

Made to his mistress’ eyebrow

This is the third stage of man's life. Now he is a grown up  and assumes the form of a lover. It is the time when he loves his beloved . He sighs like a furnace and an oven. He writes a song in praise of his beloved's eyes and eye brow. He also sings such songs  and burns in his emotions.

In this stage man become young and strong.The period of his emotional life starts.He becomes strong and healthy.He becomes aware of the presence of sexual passion in him.He begins to make love with a young and beautiful girl.He makes sighs.His acts of making sighs at the failure of his love is compared to the burning of the furnace .He writes tragic and unhappy songs in praise of the charming eyes of his beloved .In this way ,He satisfy his emotional nature.
                                                                                                        B.A punjab university 2014
                                                                                                       English paper A (first group)

  Fourth stage

Then a soldier

Full of strange oaths

and bearded like the pard

Jealous in honour

sudden and quick in quarrel

Seeking the bubble reputation

Even in the cannon’s mouth

In these lines the poet shows the fourth stage of a man’s life. When he matures, he becomes a soldier. He takes strange oaths. He has a beard like a tiger or a leopard. He is fierce like these animals. During this stage of life, man is jealous of honour of other. He is very quick ­tempered and owns quarrels. Since he is warm-blooded, he looks for temporary reputation and fame. To achieve this temporary fame, he is even ready to go into the mouth of a gun. He does not bother for dangers .
Fifth Stage
And then the justice

In fair round belly with good capon lin’d

With eyes severe and beard of formal cut

Full of wise saws and modern instances

And so he plays his part.
    In the fifth period a Judge with formal beard ,fairly round belly,and severe eyes appears on the stage of the world.He knows many proverbs and can quote a lot of modern instances
many preverbs and can quote a lot of modern instances.
In the sixth stage he becomes an old man. lean and weak. There are whistles in his voice and he wears glasses on his nose . He  keeps a small bag with him and the world is so vast for his weak body.
Sixth stage

The sixth age shifts

Into the lean and slipper’d pantaloon

With spectacles on nose and pouch on side
 In the sixth stage he becomes an old man. lean and weak. There are whistles in his voice and he wears glasses on his nose . He  keeps a small bag with him and the world is so vast for his weak body.
seventh stage

Turning again toward childish treble, pipes;

And whistles in his sound.
 Last scene of all

That ends this strange eventful history

Is second childishness and mere oblivion

    Sans teeth, sans eyes, sans taste, sans everythin
This is the last stage of men’s life. In this stage he changes from his old age to the oldest age. No dought this is a strange stage . In this period all the life which has been  full of interesting events, comes to an end. and man becomes child once again. This is like men's second childhood.
In this stage he is childish and like a child. At this stage he forgets  everything. His memory becomes  weak and he loses teeth, eye-sight and taste. He is without everything and this is the stage in which he completes the drama of his life and leaves the stage of this world for the next.