Comedy is a word that Greeks and Romans confined to descriptions of stage-plays with happy endings. In the Middle Ages, the term expanded to include narrative poems with happy endings and a lighter tone. In this sense Dante used the term in the title of his poem, La Divina Commedia. As time passed, the word came more and more to be associated with any sort of performance intended to cause laughter.
The phenomena connected with laughter and that which provokes it has been carefully investigated by psychologists and agreed upon the predominating characteristics are incongruity or contrast in the object, and shock or emotional seizure on the part of the subject. It has also been held that the feeling of superiority is an essential factor: thus Thomas Hobbes speaks of laughter as a "sudden glory." Modern investigators have paid much attention to the origin both of laughter and of smiling, as well as the development of the "play instinct" and its emotional expression.
Much comedy contains variations on the elements of surprise, incongruity, conflict, repetitiveness, and the effect of opposite expectations, but there are many recognized genres of comedy. Satire and political satire use ironic comedy used to portray persons or social institutions as ridiculous or corrupt, thus alienating their audience from the object of humor.
Parody borrows the form of some popular genre, artwork, or text but uses certain ironic changes to critique that form from within (though not necessarily in a condemning way). Screwball comedy derives its humor largely from bizarre, surprising (and improbable) situations or characters. Black comedy is defined by dark humor that makes light of so called dark or evil elements in human nature. Similarly scatological humor, sexual humor, and race humor create comedy by violating social conventions or taboos in comedic ways.
A comedy of manners typically takes as its subject a particular part of society (usually upper class society) and uses humor to parody or satirize the behavior and mannerisms of its members. Romantic comedy is a popular genre that depicts burgeoning romance in humorous terms, and focuses on the foibles of those who are falling in love.
The word "comedy" is derived from the Classical Greek κωμῳδία, which is a compound either of κῶμος (revel) or κώμη (village) and ᾠδή (singing): it is possible that κῶμος itself is derived from κώμη, and originally meant a village revel. The adjective "comic" (Greek κωμικός), which strictly means that which relates to comedy is, in modern usage, generally confined to the sense of "laughter-provoking". The word came into modern usage through the Latin comoedia and Italian commedia and has, over time, passed through various shades of meaning.
In ancient Greece, comedy seems to have originated in songs or recitations aporpos of fertility festivals or gatherings, or also in making fun at other people or stereotypes. In the Poetics, Aristotle states that comedy originated in phallic songs and the light treatment of the otherwise base and ugly. He also adds that the origins of comedy are obscure because it was not treated seriously from its inception.
Northrop Frye described the comic genre as a drama that pits two societies against each other in an amusing agon or conflict. He depicted these two opposing sides as a "Society of Youth" and a "Society of the Old", The Anatomy of Criticism. 1957, but this dichotomy is seldom described as an entirely satisfactory explanation. A later view characterizes the essential agon of comedy as a struggle between a powerless youth and the societal conventions that pose obstacles to his hopes; in this sense, the youth is understood to be constrained by his lack of social authority, and is left with little choice but to take recourse to ruses which engender very dramatic.
Types of comic drama 
- Ancient Greek comedy, as practiced by Aristophanes and Menander
- Ancient Roman comedy, as practiced by Plautus and Terence
- Ancient Indian comedy, as practiced in Sanskrit drama
- Burlesque, from Music hall and Vaudeville to Performance art
- Citizen comedy, as practiced by Thomas Dekker, Thomas Middleton and Ben Jonson
- Clowns such as Richard Tarlton, William Kempe and Robert Armin
- Comedy of humours, as practiced by Ben Jonson and George Chapman
- Comedy of intrigue, as practiced by Niccolò Machiavelli and Lope de Vega
- Comedy of manners, as practiced by Molière, William Wycherley and William Congreve
- Comedy of menace, as practiced by David Campton and Harold Pinter
- comédie larmoyante or 'tearful comedy', as practiced by Pierre-Claude Nivelle de La Chaussée and Louis-Sébastien Mercier
- Commedia dell'arte, as practiced in the twentieth-century by Dario Fo, Vsevolod Meyerhold and Jacques Copeau
- Farce, from Georges Feydeau to Joe Orton and Alan Ayckbourn
- Laughing comedy, as practiced by Oliver Goldsmith and Richard Brinsley Sheridan
- Restoration comedy, as practiced by George Etherege, Aphra Behn and John Vanbrugh
- Sentimental comedy, as practiced by Colley Cibber and Richard Steele
- Shakespearean comedy, as practiced by William Shakespeare
- Dadaist and Surrealist performance, usually in cabaret form
- Theatre of the Absurd, used by some to describe Samuel Beckett, Harold Pinter, Jean Genet and Eugène Ionesco
- Oxford English Dictionary
- Francis MacDonald Cornford, The Origin of Attic Comedy, 1934.
- This list was compiled with reference to The Cambridge Guide to Theatre (1998).
- Aristotle, Poetics.
- Buckham, Philip Wentworth, Theatre of the Greeks, 1827.
- Marteinson, Peter (2006). On the Problem of the Comic: A Philosophical Study on the Origins of Laughter. Legas Press, Ottawa, 2006.
- Pickard-Cambridge, Sir Arthur Wallace
- Dithyramb, Tragedy, and Comedy , 1927.
- The Theatre of Dionysus in Athens, 1946.
- The Dramatic Festivals of Athens, 1953.
- Raskin, Victor, The Semantic Mechanisms of Humor, 1985.
- Riu, Xavier, Dionysism and Comedy, 1999. 
- Sourvinou-Inwood, Christiane, Tragedy and Athenian Religion, Oxford University Press, 2003.
- Wiles, David, The Masked Menander: Sign and Meaning in Greek and Roman Performance, 1991.