Comedy resists definition. Some have argued that it is an adaptive strategy providing relief from the tragic or the mundane through laughter. To elicit this laughter, comedy assumes many forms. Types of comedy include slapstick, farce, black comedy wordplay burlesque, satire, vaudeville, situation comedy on television, stand-up comedy clowning, mime, etc. However, some material considered "comedy" may not necessarily induce laughter. Comedy may simply refer to a presentation that focuses on the lighter side of life. In general, the term "comedy" has certain genre connotations, while the term "humor" refers to a comic quality causing amusement, such as dry humor, or buffoonery. Because of cultural assumptions regarding the nature and function of comedy many members of marginalized groups (with respect to race, class, ethnicity or religion) have made their way into the entertainment industry through comedy while the world of serious drama has been harder to penetrate. Women, however, have experienced more difficulty being taken "seriously" as comedians.

Since the end of the Second World War, one of the most important developments in American comedy has been the advent of the situation comedy on television. This form of comedy emerged from a long history of comedy in America—characterized by vaudeville, film comedy (including the silent film comedy of such luminaries as Charlie Chaplin, Buster Keaton and Harold Lloyd), radio comedy stand-up comedy and variety television shows. Since the introduction of the VCR, video rentals, and cable television in the late 1970s, there has been much crossover between these various comedic venues.

Many of the American comedians who started out with stand-up routines in comedy clubs and then moved on to film and/or television careers have become quite successful.

(Consider the careers of Woody Allen, Bill Cosby, Ellen DeGeneres, Robin Williams, Whoopi Goldberg and Jerry Seinfeld—to name just a few.) Prior to this route, many American comedians started out in vaudeville (George Burns and Gracie Allen, for example, who went on to begin one of the first television situation comedies, The George Burns and Gracie Allen Show, which ran from 1950–8). Comedian Bob Hope also developed a genre of television specials based on his shows for American troops abroad, rebroadcast on holidays.

Still, there are comedians who are known primarily for certain types of comedy.

Analysts have divided comedians into various types, including social commentators, politicos, observationalists, fringe players, wiseguys, etc. Other notable American comedians of the postwar era include (in addition to those mentioned above): Lily Tomlin, Eddie Murphy, Jackie Gleason, Jim Carrey Chevy Chase, Gilda Radner, Walter Matthau, Margaret Cho, Jack Benny Billy Crystal, Goldie Hawn, Jim Belushi, Jerry Lewis, Dean Martin, Johnny Carson, Jane Curtin, Richard Pryor, Lenny Bruce, Lucille Ball, Desi Arnaz, David Letterman, Sandra Bernhard, Flip Wilson, Jay Leno, Bill Murray John Leguziamo, Mary Tyler Moore, Spalding Gray Mel Brooks, Carl Reiner, Cheech and Chong, Roseanne, Steve Martin, Marilyn Monroe, Gene Wilder, Dan Ackroyd, Redd Foxx and Henny Youngman.