I definitely agree with shakespeareguru but would like to add that The Winter's Tale falls into the category of Shakespeare's Late Plays, (Cymbeline, Pericles, The Winter's Tale and The Tempest).
All of these plays emerged out of the romance tradition. These plays all deal with loss and gain. They all have "happy"endings.
It would appear that by now, as a writer, Shakespeare has explored comedy, tragedy, and history plays. The romance tradition gave him a new play ground, so to speak, as a playwright. We see him trying things never before done in theatre. The Winter's Tale has what has been called a broken back structure. The first three acts of the play indicate a tragedy. It is dark and wintry, full of death both literally and figuratively. One of the saddest death's was young Mamillius. Ironically, he spoke of the winter time being a time for sad tales.
Shakespeare establishes a beautiful bridge with the Old Shepherd, who tells his son when the youth reports the death of Antigonus, "...Now bless thyself. Thou metest with things dying, I with things new-born..."(Act III, scene 3)
Shakespeare then jumps ahead in time and we get the fresh breath of spring and the introduction of the next generation. Out of death comes life. Both fathers are dead in their own way. Leontes is spiritually dead as a result of his earlier actions. Polixenes is dead to his own feelings therefore he cannot understand his son's love for this "peasant" girl. Florizel recognizes her nobility which radiates from her. (This is similar to the noble radiation of both Marina and Imogen.) Each man has a rebirth due to the innocence and purity of their children's love.
The title of the play operates on a variety of levels which is the beauty of Shakespeare.
I personally think that in the Late Plays, Shakespeare was having as good time as a writer, breaking all the established rules.
Shakespeare often gave enigmatic titles to his plays -- Twelfth Night, As You Like It, All's Well That Ends Well, Much Ado About Nothing and The Winter's Tale. It is hard to know exactly why it was given this title, but there are theories.
Some have argued that the title suggests the importance of the passage of time or the qualities of the seasons. In Winter, things freeze and wait for the thawing and renewal of Spring, just as Hermione "freezes" in anticipation of Leontes rebirth and renewal at the play's end.
Others have suggested that it hints at the fantasy and allegory of the play. The play certainly doesn't fit any neat category and is often called a Romantic Tragi-Comedy, quite a jumble of dramatic genres. The term Tale suggests a story handed down through time, bearing a lesson of value.
And then there is the line spoken by Mamillius in Act II, scene i. Mamillius is Leontes heir, but killed by him in a jealous rage that he might not be his son. In discussing what sort of tale Hermione should tell her son to amuse him, Mamillius says:
A sad tale's best for winter: I have one
Of sprites and goblins.
Whether Shakespeare means the audience to notice this particularly and pay attention to this comment that his "winter's tale" is a "sad" one "of sprites and goblins" is certainly worth considering.
The play winter's tale (shakespeare) was named by that name because in the winter season , everything becomes relatively bare : people have negative feelings(somehow)bec. they sit most days of the month at home because of coldness n noone is going here n there but only sitting alone....Leontes was also lonely because of his negative feelings towards Hermione (the innocent wife) and Polixenes (the blameless friend) and Camillo (the good lord) so that lead him to be like the bare tree which has no fruits or leaves.