"What makes a movie a movie is the editing," says Zach Staenberg in the documentary "The Cutting Edge."

Admittedly, Staenberg is an editor, most famously of the "Matrix" movies, but he's not wrong. Editing can create emotion, speed up or slow the pace, explore the psychology of a character or find meaning that even the actors and writers didn't know was there. Along with the director, an editor decides what we look at and for how long.

You'll find examples in the clip-filled and entertaining "The Cutting Edge," which examines the art of editing and which you can watch for free on YouTube. In it, we see editing legend Walter Murch solve "problems" created in the filming of "Cold Mountain," hear his compadres talk about why it's so much fun to work on chase scenes, learn why women broke into the craft much earlier than others (spoiler alert: sexism worked in their favor) and see how famous scenes might have been altered if an editor had made different choices.

The job is one of the most misunderstood in Hollywood. You'll often hear it said, "Why didn't the editor make it shorter?," which misrepresents the role of an editor, who is more likely to determine how individual shots fit within scenes than the movie's length (that's a director's or producer's call). Even Oscar voters get it wrong. They generally throw up their hands and award the editing statue to the best picture winner, unless there's a flashier option ("Whiplash," cut to the rhythms of jazz, or "All That Jazz," where almost-subliminal cuts plunge us into the mind of its out-of-control protagonist) or a movie with cars banging into each other ("The French Connection," "Grand Prix" and "Bullitt" all won for their editing).

"The Cutting Edge" is mostly about American movies, but it pays tribute to the pioneering '50s and '60s French editors whose jittery technique spread to Hollywood films such as "Bonnie and Clyde" and continues to this day in, for instance, "Moonlight."

It also acknowledges the founders of editing, many of them Russian, who figured out basics such as the Kuleshov Effect, which established that you could juxtapose a blank-faced actor with an image of, say, a birthday cake or a dead body, and the audience would interpret the blank expression as showing emotions such as delight or horror. We don't notice it, but this effect is in literally every movie. When the Walker Art Center's Mediatheque reopens, you can view dozens of examples from Sergei Eisenstein's "Battleship Potemkin," Dziga Vertov's "Man With a Movie Camera" and D.W. Griffith's "Intolerance."

These greats say a lot about the editors who decide what makes the cut.

Raging Bull (1980)

Martin Scorsese is making an adaptation of "Killers of the Flower Moon" right now, and that means editor Thelma Schoonmaker is making a new movie, too. She has been with Scorsese in the editing suite since 1967. She's won three Oscars for Scorsese movies (triple his total!), including this one, in which the slowed-down, sped-up, knocked-sideways boxing scenes are the most striking.

Jaws (1975)

The tension created in "Jaws" has so much to do with Verna Fields' skill that, in "Cutting Edge," Steven Spielberg says that they often battled over her insistence that eliminating just two frames would make most scenes better, and that she was always right.

Memento (2000)

There's no more obviously "edited" movie, since half of Christopher Nolan's tricky thriller is in chronological order and half is backward. That it even makes sense, and that the actors' performances track so beautifully, was celebrated by the Motion Pictures Editors Guild, which called Dody Dorn's effort the 14th best-edited movie of all time. (The out-of-order work of another great, the late Sally Menke, on "Pulp Fiction," may have inspired Dorn.)

Mad Max: Fury Road (2015)

Another editing Oscar, another movie-long chase scene. George Miller's masterwork is nonstop action, so heavily chopped up that it could be chaotic, but even as trucks are doing back flips and trapeze artists are firing cannons at each other, editor Margaret Sixel makes sure it's clear where we are and what is going on.

Out of Sight (1998)

Possibly inspired by a scene from "Don't Look Now," a sexy, mixed-chronology George Clooney/Jennifer Lopez snogfest gets most of the attention, but I love the little moments where editor Anne V. Coates and director Steven Soderbergh cut away from the main character to someone in the gifted cast for a reaction shot.

Rear Window (1954)

At least as far back as "Battleship Potemkin" in the silent era, movies have used editing to build suspense with alternating points of view. An almost unbearably tense example is the practically dialogue-free, George Tomasini-edited scene here where Grace Kelly stumbles upon a murderer while Jimmy Stewart watches from across the courtyard, unable to intercede.

Mulholland Drive (2001)

David Lynch has said that a key to enjoying his movies is a willingness to get lost. Mary Sweeney, who edited "Mulholland" and several others for Lynch, has said that she's like the moviegoing public's first pair of eyes because she usually doesn't know what's going on when she starts working on his films. As a result, a big part of her job is massaging footage to that moment where a dream logic emerges for her (and, hopefully, audiences).

Chris Hewitt • 612-673-4367