The Way of the World is a Commedy of manner-Justify
(Reference: Kathleen Morner, Ralph Rausch, NTC's Dictionary of Literary Terms)
When Charles II ascended to the throne again and monarchy was restored in 1660, the then English society got relief from the suppression of the stern Puritan rules & regulations. But, this led the society to over indulgence of sensual pleasure and immoral acts. The king himself was not a moral human at all. The society started losing their sense of priority. Immoral acts enveloped the society's good sides. While theaters were being flourished, writers & dramatists were patronized by the rulers, bad poets & notorious actors-actresses took birth (ref: John Dryden's McFlecknoe). Women were being disregarded and felt insecure. So, most of the women's primary goal became to charm men, and to make their own future secure anyhow. They used to pass time by gossiping, playing cards, having walks in the park with their male admirers, whereas, men used to pass time playing cards and drinking chocolate at the chocolate house. Extra-marital affair was a common phenomenon among the couples. But, neither husband nor wife expressed their internal feelings in front of others even if they hated each other. They always wore a facade. This was the condition of the Restoration society.
These social behavior and manners are depicted in many plays by playwrights like William Congreve, Richard Brinsley Sheridan of the age. These plays highlight the social follies satirically; the characters represent themselves as a part of that flawed society. Though their individual traits or manners are always foregrounded, the characters are represented as a collective unit, not as individuals. But the main target of such witty, satiric comedies is the society as a whole, not the individual characters. Since the manners, customs and rules of the society are highlighted, these are called comedy of manners. And as The Way of the World fulfills these conditions, this is a successful comedy of manner of that age.
Congreve's The Way of the World, shows many a portraits: Mirabell as a beau already done harm to Mrs. Fainall, Millament as a beautiful young lady feeling inertly insecure who always remains surrounded by some foolish men, Marwood's making love with the husband of Mrs. Fainall, Marwood's habit of eavesdropping and harming Mirabell & Milament being refused by Mirabell, Mrs. Fainall's wedding to Fainall to secure her future, and most importantly, Lady Wishfort's untiring willingness to make herself look young & beautiful and thus making herself more vulnerable, all these portraits are exact depiction of 18th century urban society. Through witty dialogues and careful handling of the plot, Congreve has superbly made it a successful Restoration comedy of manner.