he best jokes in the most recent ''Austin Powers'' sequel -- the ones that aren't about flatulence or Fat Bastard or both -- are the jokes about movies, especially about spy movies and most especially about ''Austin Powers'' movies themselves. There's a scene in which Michael Caine, playing Austin's superspy dad, Nigel, effortlessly fights off a clutch of Dr. Evil's henchmen, the last of whom he persuades to fall over without even being punched: since the henchman is nameless (to the extent of not even possessing a name tag, as Nigel points out) and since the entire purpose of nameless henchmen is to topple at the slightest feint from a man like Nigel, why doesn't he just lie down immediately and save them both the trouble? Later, Austin and his comrade Foxxy Cleopatra meet with a Japanese businessman who makes what seems to them a series of naughty remarks; like the audience, they're following the English subtitles, portions of which are washed out because they're printed over a white background.

Not quite parody but possibly ironic and probably postmodern -- what these jokes are, as the former English majors out there will no doubt recognize, is meta. ''Meta'' is a liminal term these days; it's creeping more and more into everyday conversations, even if it's not nearly as widespread as, say, ''irony.'' Some people talk about meta all the time. Recently a friend and I were e-mailing back and forth, trying to sort out our plans to catch an evening movie, when we started to discuss how we were going to make the decision itself -- should we stick to e-mail or switch to instant messaging or the phone? ''This is getting too meta,'' he wrote. ''Just call me.'' Other people, including another movie-steeped friend, may not recognize the term ''meta,'' but they know exactly what it is all the same; on the basis of a quick definition, my friend could instantly list a half-dozen good examples: ''Oh, I get it. 'Beavis and Butthead' was a music-video show about watching music videos, and that teen film 'Not Another Teen Movie' had a character whose only name was the Token Black Guy.''

It's easy to come up with examples in other media, too. At the hit Broadway musical ''Urinetown,'' you can hear two characters -- a little girl and a policeman -- say things like ''Of course she loves him, Little Sally. He's the hero of the show. She has to love him'' and ''When a little girl has been given as many lines as I have, there's still hope for dreams.'' If, looking for a cheaper thrill, you rent the horror film ''Scream,'' a feast of meta devices, you'll see a scene in which a teenage B-movie buff explains to fellow partygoers that ''there are certain rules one must abide by in order to successfully survive a horror movie. For instance, No. 1: You can never have sex,'' just before the camera cuts to the film's heroine losing her virginity upstairs.

Flipping through TV channels, you might stumble across a rerun of ''The Drew Carey Show'' in which the sitcom's star tells the camera that the cast is miffed about not receiving any Emmy nominations and has put together the following episode in order to fish for some. What follows is a sendup of the kind of ''serious'' TV revered by awards judges -- hospital-bed death scenes, brooding soliloquies and simple-minded efforts to ''address'' such social issues as gun control and illiteracy -- with the actors zestily hamming it up. An entire season of ''Seinfeld'' concerns Jerry's development of a sitcom ''about nothing,'' a sitcom that's clearly ''Seinfeld'' itself. During commercial breaks, you might catch an ad in which one man sings the praises of an automobile to another. ''You sound like a car commercial,'' his friend jokes. ''Didn't they tell you?'' the first man says significantly. Once an arty experimental theater technique used by people who wrote plays with titles like ''Six Characters in Search of an Author,'' meta is now being used to tout antilock brakes. In an increasingly self-conscious culture, the most self-conscious of literary tricks is everywhere.

Defining meta, though, can be tricky. A prefix, it comes from the Greek for ''beside,'' ''after'' or ''change.'' The critic Herbert Kohl, in his 1992 book ''From Archetype to Zeitgeist,'' takes a pretty good shot at explaining it. Meta, he writes, ''when used with the name of a discipline, designates a new but related discipline designed to deal critically with the original one.'' Metamathematics, for example, is ''the critical study of the nature of mathematical systems,'' and metapsychology is ''the critical study of psychology as a discipline.'' ''Metaphysics,'' one of the most familiar derivations, is the title of the work by Aristotle that follows his ''Physics'' and that deals with the ultimate nature of the universe. How did meta get from statements like ''2+2=4 is valid within Frege's formal system'' and speculation about the first principles governing causality to a dapper Japanese gentleman inadvertently making potty jokes to a kitschy secret agent? It traveled by way of metafiction, a literary school of the 1960's and 70's. Metafiction is fiction that openly admits it's an artificial creation -- as opposed to naturalism, in which art strives to represent real life. (The same idea got tried out even earlier in the theater. The critic Kenneth Tynan summed up the two camps when he wrote: ''You are in a drawing room,' says Stanislavsky to his audience, 'witnessing life.' 'You are in a theater,' says Brecht, 'witnessing actors.''')

John Barth, one of metafiction's stars (others include John Hawkes, Donald Barthelme and Robert Coover), wrote a story called ''Lost in the Funhouse'' in which he refers to a character as ''Magda G------'' and then goes on to explain: ''Initials, blanks, or both were often substituted for proper names in 19th-century fiction to enhance the illusion of reality. It is as if the author felt it necessary to delete the names for reasons of tact or legal liability. Interestingly, as with other aspects of realism, it is an illusion that is being enhanced, by purely artificial means.'' The metafictionists liked to point out that people are always telling stories and that stories have their own laws, utterly different from the laws that govern real life. You can see those rules played out in more than just novels; they prevail in everything from fairy tales and gossip to comic strips, movies and pornography.

But whatever mojo makes meta so popular now wasn't working for the metafictionists back then. With the exception of Barth at the beginning of his career, they never found a large audience outside of academics and critics; readers complained that the whole enterprise came across as mandarin, aloof and theoretical.

Perhaps that's because a lot of metafiction has a whiff of the schoolmaster about it. The novelist David Foster Wallace captured the queasy subtext of literary metafiction in a short story, ''Octet,'' that is a satirical metafiction about metafiction itself. The story's ''author,'' voicing his distress through footnotes, frets about his inability to pull off the intended ''cycle of very short belletristic pieces'' in the form of pop quizzes. What he wants to avoid, he says, is the ''now tired'' meta device of ''the dramatist himself coming onstage from the wings and reminding you that what's going on is artificial and that the artificer is him (the dramatist) and but that he's at least respectful enough of you as reader/audience to be honest about the fact that he's back there pulling the strings, an 'honesty' which personally you've always had the feeling is actually a highly rhetorical sham-honesty that's designed to get you to like him and approve of him (i.e., of the 'meta'-type writer) and feel flattered that he apparently thinks you're enough of a grown-up to handle being reminded that what you're in the middle of is artificial (like you didn't know that already, like you needed to be reminded of it over and over again as if you were a myopic child who couldn't see what was right in front of you).''

In other words, metafiction could be pretty patronizing and, what's more, puritanical in the particular, medicinal fashion of the American avant-garde, which is so often eager to relieve its audience of the oppression of a good time. By comparison, Wallace's own vamp on the endlessly receding hall of mirrors in which his overly cerebral and self-conscious storyteller has trapped himself is much nimbler. Contemporary writers give ordinary people more credit for knowing the difference between real life and playacting.

Zadie Smith, describing the frankly bogus good-versus-evil theatrics of a professional wrestling match in her new novel ''The Autograph Man,'' explains that the fans know the wrestlers ''are not here to express genuine feelings, or to fake them and dress them up natural like on TV. . . . This afternoon, these two hulking men are here to demonstrate Justice. The kind Mr. Gerry Bowen (Block M, Seat 117) can't get from the courts in compensation for his son's accident; the kind Jake (Block T, Seat 59) won't get from school whether he chooses to squeal on those bastards or not; the kind Finn (Block B, Seat 10) can't seem to get from girls no matter what changes he makes to his wardrobe or record collection or personal hygiene.''

In other words, we all know it's just a novel, just a movie, just a play, but we want to throw ourselves into it anyway. We know this isn't like real life -- that's why we're here, and we'd rather not be lectured on the difference. Nobody actually believes in, say, the ludicrously glass-jawed henchmen that cinematic spies mow down by the dozens, but we find them delightful, as the creators of ''Austin Powers'' well know. Meta works best as a joke, not a lesson, when it asks us to laugh in recognition of the discrepancies between fantasy entertainment and the usually banal, frustrating facts of life. One episode of ''The Simpsons'' makes a meta nod in this direction, opening with Homer and Marge sitting on the family couch, looking bored. ''I guess we're not having an adventure this week,'' Marge says. Even cartoon characters can't expect to have lives as exciting as . . . cartoon characters.

Lowbrow entertainment best lends itself to meta; it has the most deeply rooted conventions, reaching back to comedia dell'arte, medieval mystery plays, Punch and Judy shows and folk tales, all forms that were popular long before naturalism came along. We tend to forget that the notion that art should be made to resemble real life isn't traditional at all. It's pitifully arriviste, like the thin crust representing the Age of Man in those timelines showing the geological epochs in Earth's history. Indeed, when the artists of modernism and postmodernism decided to play up the artificiality of their work, they weren't doing something new; they were reviving something very, very old. When Zadie Smith, describing two wrestlers going at it, writes, ''All of a sudden they run at each other once more and if you have a better phrase than like thundering elephants insert it here [ ],'' she's tipping her hat to Laurence Sterne's ''Tristram Shandy,'' a book written in 1759, before the novel was properly born.

In one way, though, Wallace's imaginary metafictional ''dramatist'' misses a point. Meta touches on the stories we, like children, demand to hear over and over again, albeit with artful variations. They offer us the satisfactions of ritual rather than the boredom of repetition, and however familiar their devices, they still work. ''Urinetown'' is an extended joke about the preposterousness of musicals: Officer Lockstock and Little Sally discuss the importance of avoiding ''too much exposition,'' note the discrepancy between the show's ''happy'' music and its grim plot and lament its ''terrible'' title. The musical numbers themselves fall into the usual categories -- love song, anthem, faux gospel -- and though they're hung on a storyline that refuses to plausibly support them, they're a blast nonetheless. The teenagers in ''Scream'' know the conventions of slasher movies so well, they provide a running commentary on them as they unfold. In the film's final sequence, the supposedly dead killer returns to announce: ''This is the moment when the supposedly dead killer comes back to life for one last scare.'' And here's the rub: it's still frightening. Wes Craven, the director of ''Scream,'' even made an installment of his ''Nightmare on Elm Street'' series in which the characters use a screenplay of the movie they're in to outwit the series' monster -- and that's scary, too.

Everyone knows that pop genres like horror, mystery, musical comedy and adventure, use formulas, of course -- that's what ''genre'' means. The highbrow ideal says that art should be original and (usually) true to life; those are supposedly the hallmarks of quality. But we now live in a society more steeped in stories than any that has gone before. In a given week, we may see a movie or two, rent a couple of videos, catch a half-dozen (or more) television programs, listen to the radio, play CD's and read newspapers, magazines or a book. The more of this we absorb, the more clearly we see that every good story uses some kind of formula. After only a couple of seasons of MTV's ''Real World,'' the show's participants could talk authoritatively about which standardized role -- the naive virgin, the bitch, the gay housemate emerging from the closet -- each person would assume. Suddenly, everything starts to look like a genre.

In his book ''American Scenarios: The Uses of Film Genre,'' Joseph W. Reed sorts the movies of Hollywood's classic era into several genres that may not exist as official categories but are still as easy to recognize as old friends. In addition to War, Women's and Westerns, there are Inventor, High School, Jungle, Psychiatrist, Escape and Southern pictures, too. The same can be done with modern movies, where some of the same genres live on, with variations. We could add to Reed's list such genres as the Incurably Ill Child movie, the Ghetto Kid Makes Good movie, the Girlhood Friends Working Out Their Issues movie and the European Food movie, flooding at us in such volume that they can hardly pretend to be unique. Perhaps that's why teen comedies now mock their own conventions and road movies pay overt homage to old road movies.

Then there are artier efforts that get labeled meta even when they don't really hit the mark, like Steven Soderbergh's ''Full Frontal,'' in which scenes of a bunch of loosely connected characters in Los Angeles shot on digital video alternate with scenes from a film that some of those characters will go on to make. Film-within-a-film isn't meta and neither are films about filmmakers -- otherwise ''Singin' in the Rain'' would be meta and it's not. However, the film-within-the-film in ''Full Frontal'' is a little bit meta; in it, a black actor tells a white journalist that black male movie stars never get to do real love scenes with white actresses, and when the characters fall in love at the end, they move in to kiss each other and then turn away at the last minute. But ''Full Frontal'' itself never jokes about the genre it belongs to, the Indie Ensemble picture; after all, the whole point of successful Hollywood filmmakers doing movies about middle-class New Yorkers and Angelenos with career troubles is to feel that at last they are getting to demonstrate their artistic chops by depicting real life.

A better portrait of the flickering interaction between culture and reality in the belly of the beast is ''Adaptation,'' the most recent film by Spike Jonze and Charlie Kaufman. (Making a movie about the movie's own screenwriter recalls the now common postmodern literary stunt of including in a novel a character with the novelist's name -- Kaufman's following in the footsteps of Philip Roth and Martin Amis.) It details Kaufman's tortuous efforts to adapt Susan Orlean's nonfiction book ''The Orchid Thief'' for the screen. ''I don't want to ruin it by making it a Hollywood thing, like an orchid-heist movie or something . . . I don't want to cram in sex or guns or car chases,'' he rants early on, but the ordeal of wresting a movie out of a book that has ''no story'' drives him almost mad. Eventually, mystery and intrigue creep into the plot of ''Adaptation,'' and by the time the film veers into a ludicrous string of Hollywood ''action thriller'' cliches -- a chase through an alligator-infested swamp and a bogus yet strangely affecting moment of insight -- we realize that Kaufman has succumbed to Hollywood's imperatives. ''Adaptation'' curses the contrivances of blockbuster filmmaking so thoroughly that by the time it resorts to them, the results are amusing, clever, even wise. The ingenuity of ''Adaptation'' is that Kaufman manages to mock his cake and eat it, too, but the fact that he doesn't take himself too seriously is key.

The more high-minded it is, apparently, the easier it is for meta to annoy. Ian McEwan's novel ''Atonement'' became a best-seller earlier this year, but I keep discovering people who were irritated, as I was, by the ending (which I'm about to discuss -- so jump ahead if you don't want it spoiled). In the book's final pages, it is revealed that the preceding narrative has been one character's fictionalized account of events, which in ''real life'' didn't end quite so satisfyingly. The novel is an exquisite technical achievement, but the apparent message of that ending -- that actual experience rarely offers closure or redemption and that we should always be aware that novels aren't like life (going on about how fiction is a ''lie'' is one of the more irritatingly arch affectations novelists are prone to) -- is exasperating. Anyone smart enough to read an Ian McEwan novel already knows this, and it's hard not to feel, like the writer in Wallace's ''Octet,'' that you're being talked down to. This is meta of the old school, solemn and scolding.

By contrast, Michael Winterbottom's supple ''24-Hour Party People,'' a biopic about Tony Wilson, an impresario of the Manchester music scene during the 1980's, is meta at its best. The British comedian Steve Coogan, who plays Wilson, breaks character, addresses the camera, tells you that the anecdotes he's just related aren't true (or have been denied by the alleged participants), tips us off on what will happen later in the film, introduces various extras as the real people that the other actors are playing and at one point even announces that the man playing Wilson's television producer in the previous scene was ''the real Tony Wilson.'' All this serves to undermine Wilson's version of events and at the same time to demonstrate that what actually happened doesn't really matter that much. Wilson's gift for enthusiasm, for embellishing the truth, is his great talent, his very life a testimony to the power of meta as the falsehood you believe in anyway. His tireless mythologizing of the scene is what made living in his Manchester (whether or not it was truly like ''Renaissance Florence,'' as he insisted) so much fun.

When meta intends to teach us a lesson -- that is, when it's a drag -- it's usually instructing us that we shouldn't confuse fiction with real life. But as Wilson's own experience shows, sometimes the right story, well used and passionately espoused however false it at first seems to be, is exactly what real life needs. At its most anarchic and least instructive -- that is, as it flourishes today -- meta suggests that distinguishing between truth and fiction counts for less than knowing a terrific story when you have seen one and relishing it regardless of its authenticity. If to be human is partly a matter of believing, as Lewis Carroll's White Queen did, in ''as many as six impossible things before breakfast,'' better that we understand what we're doing when we select those impossible things, knowing not only how much we may suffer from choosing the wrong ones but also how much joy can be found in embracing the right lie. Manchester may not ever be Florence in the Renaissance (if even Florence in the Renaissance was), but why should that keep us from dancing all night?