Zoha, though I think that a very similar question is already answered in eNotes, I shall try my best to give you a satisfactory reply.
In his The Way of the World, Congreve has presented the portrait of the aristocratic 18th century English society in such a manner that the drama has itself become a disparaging document against the social customs with a motive to emphasize on the re-installation of morality.
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. 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. The main target of such witty, satiric comedies is the society as a whole, not a particular theme or character, since the purpose of the play is to teach a moral via highlighting the social follies and criticising the manners and customs of the society.
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 depictions of 18th century urban society. Through witty dialogues and careful handling of the plot, Congreve has superbly made it a successful Restoration comedy which is a social critique.
Congreve's The Way of the world is a perfect instance of criticisisng the restoration society. the characters represent the trechery and cladestine society. ladies deceive their husbands and so as the males. Mr. Fainall marries Lady Wishforts's daughter for property and on the other hand he keeps on love affair with mrs. Marwood, without his spouse's knowledge. again, mrs.fainall had a love affair with mirabell that she has hidden from her hubby. lady wishfort had an affair with mirabell.
congeve presents a totally puzzled situation of the then society. he is the critique of the society. the socity was all about money, property, and scandal. people couldn't live without extra marital affair, lavish living, being busy doing nothing.
congreve and sheridan take the charge of reforming the society by poking it on its core. wine, theatre, conspiracy, and discussing about other's scandal and character was the chief concern of the restoration period.
their's a mask in eveybody's face and behind the mask we can see a black, deceiving character that can naot be trusted.
mrs. marwood who pretends to be the best friend of lady wishfort is actually the lady love of her son-in-law who conspires to usurp the property of lady wishfort.
in a nut shell congreve is making fun of his time but with a slapstick irony and witty dialogues.