What is the significance of the cocktail party?

The significance of why the party is being given... for the characters? Or the significance of the story itself?

Story

It is unsurprising that the cocktail party of the title is a motif in the play, and also a symbol for the public lives of the characters. The beginning of the play shows the characters in a stilted, stereotypical "cocktail party" conversation, exchanging stories they have already told before. Each of the characters keeps up a certain amount of decorum and manners, as the cocktail party represents their public-facing selves. The cocktail party then reconstitutes itself at the end, but the hosts—Lavinia and Edward—are together again, and now ready to face their public.