One reason the Oscars maintain their prominence as not just the preeminent film award but the preeminent entertainment award, period, is that they don't hand out that many trophies.

The Oscars bestow honors in just 24 categories, all during their televised ceremony. Compared to, say, the Grammys' 83 prizes, the Oscars are relatively stingy — making each one precious.

And yet it's not uncommon to have absolutely no idea what some of the awards are actually for. Sure, most of us know what it means to win for acting, and the term "Best Costume Design" is self-explanatory. But what's the difference between Sound Design and Sound Editing? How long is a short film? And just what does a director do anyway?

For answers to your Oscar category questions and more, read on.

Best Picture goes to a film's producers

Glamorous actors are the center of attention on Oscar night, but the biggest award of all honors producers who are typically obscure to the mass public. This is a throwback to the Academy's roots in the Hollywood of the late silent era, when producers were the most important figures in the film industry. (That description would largely hold true — give or take a particularly prominent director — until the 1960s and '70s.)

Think of Gone with the Wind, which for a long time held the record for winning the most Oscars. The film was directed by Victor Fleming, who actually replaced original director George Cukor. But it was producer David O. Selznick who made adapting the novel into his passion project and got the film — the biggest of its era — made, and it was Selznick who took home the Best Picture trophy (via his Selznick International Pictures company).

Modern films often have dozens of producers — some of them do little more than help secure funding, or otherwise facilitate production — so the Academy has instituted a couple of regulations. To win, a producer must have a "producer" or "produced by" credit on the film, and only the three producers who have done the most work to make the film a reality (as determined by the Academy) are nominated.

However, if you look at the 2015 Oscars ballot, you'll notice several films with four producers nominated — and American Sniper has five. The explanation is simple: A team of two producers who are credited as a team and work closely together count as one producer, from the Academy's point of view. So, ultimately, three two-person teams could be nominated, allowing for a maximum of six nominees per film.

What does a director do, anyway?

The answer to this question isn't necessarily intuitive, because the popular definition of "director" is just "the person who's in charge on a movie set." And that's not wrong, but it also doesn't really dig into what a director does beyond bossing people around.

The simple answer is that in the '60s and '70s, the director replaced the producer as the most important person working on a film, in the minds of people in the industry. (Many proponents of auteur theory would argue the director had always been the most important person working on a film, and it just took that long for Hollywood to catch up. But that's neither here nor there.) The director is responsible for the overall look, feel, and tone of a film. And assuming she has final cut, she's the ultimate decider, on everything from script notes to the edit that's released to theaters. (Yes, the studio will have some say in this, but the studio doesn't get the Oscar.)

What makes the job difficult to describe, ultimately, is that different directors approach the job in different ways. Oscar-winning director William Friedkin has argued the most important part of a director's job is assembling the right cast and turning them loose. Robert Altman (director of M.A.S.H. and Nashville, among others) assembled huge ensemble casts and allowed for ample room for improvisation and exploration. British director Mike Leigh (of the recent Mr. Turner) comes up with his scripts in conjunction with his actors, who improvise until they're happy with the screenplay, and then begin the shoot.

But the most basic part of a director's job is making calls about what the film will look like. Because film is a visual medium, images are incredibly important, and great directors have immediately recognizable, signature styles. Think of, say, the many times Steven Spielberg has shot characters staring at something in wonder, or the many times Martin Scorsese has employed bravura tracking shots that follow a character through his or her native environment.

The difference between original and adapted screenplays has to do with source material

What's the difference between original screenplays and adapted screenplays? On its face, the answer is easy: Adapted screenplays are based on other works, while original screenplays are based on the writer's own idea. In practice, the distinction is a bit more complicated than that.

The 2016 nominees for Original Screenplay, for instance, include Spotlight, a film that is based on a true story. And yet because the script was based on original research by screenwriters Josh Singer and Tom McCarthy, it counts as original. If it had been based on a single primary source, like Adapted Screenplay nominee The Big Short (which adapts a nonfiction book by Michael Lewis), it would be in the Adapted category.

Why make this distinction? Because film studios or producers often buy the rights to specific books or magazine articles, and then hire screenwriters to turn them into scripts.

Making things even more confusing is the fact that the Adapted category is where all sequels compete by default. Before Sunset and Before Midnight both ended up there, because they were based on characters from Before Sunrise. The same is true for Toy Story 3 as a follow-up to Toy Story. Even though the stories and scenarios of those films were completely original, the Academy counted the sequels as adapted because their characters had appeared in prior films.

All of which brings us to one of the most confusing nominations in recent memory: Whiplash's nomination for Best Adapted Screenplay in 2015. The Academy decided to categorize the movie as Adapted because director and writer Damien Chazelle made a short film from one of the script's scenes before making a feature. But even though the script for the feature version of Whiplash predates the short film version, the Academy still ruled that the feature is "based on" the short.

The voters determine whether actors are "lead" or "supporting"

The Lead and Supporting Actor categories are the complete opposite of the two screenplay categories, in that the Academy does not make hard rulings on who's Lead versus who's Supporting. The actors and studios running their campaigns suggest where they would like to compete, but it's ultimately up to the voters, who can make up their own minds on category placement.

The Academy places all sorts of restrictions on actors — you can no longer be nominated if all of your dialogue was dubbed (like The Exorcist did when it received a nomination for Linda Blair as a possessed child, whose voice was largely dubbed), you can't be nominated twice in the same category, etc. — but its regulations don't spell out any real differentiation between Lead and Supporting.

This has prompted some consternation in 2016, with Carol's Rooney Mara receiving a Supporting Actress nomination, even though she appears in more of the film than co-star Cate Blanchett (who's nominated in Lead Actress). The Danish Girl's Alicia Vikander also could have been nominated in Lead, but ended up in Supporting.

Where this really trips up the Oscars is in two particular cases. The first involves child performers, who are often slotted into Supporting by default, even if they're the lead of a film. (The most recent example of is Hailee Steinfeld in True Grit. She's the lead actress of that film but was nominated in Supporting.) This campaign tactic doesn't always work, however. Keisha Castle-Hughes campaigned as supporting for Whale Rider in 2003, but the voters decided (accurately) to nominate her in the Lead Actress category.

The second scenario involves an actor winning acclaim for two roles in the same year and not wanting to split votes between them. (Remember: An actor can only be nominated once per category.) Thus, the studios involved usually agree to push one performance as lead and one as supporting. This happened in 2008 with Kate Winslet, who campaigned as a lead for Revolutionary Road and as supporting for The Reader. She ended up getting just one nomination, for The Reader — and she was placed in the Lead Actress category, instead of Supporting. She also ended up winning, however, so probably she didn't mind.

Finally, if a performance receives votes in both the Lead and Supporting categories (or if an actor receives multiple votes for multiple roles in the same category), the nomination goes to whichever category the actor receives the most votes in.

The foreign film award goes to a country, not a person

The person you see giving the acceptance speech for the Best Foreign Film Oscar is almost always the film's director, and that's the person who will almost always take home the physical trophy. But technically, the award goes to the film's country of origin.

Every country that's not the United States is allowed to choose one film from its local film industry to submit for Academy consideration, provided the film is not in English and was released in its country of origin between October 1 and September 30. (The foreign film calendar is slightly earlier than the Academy calendar, which runs from January 1 to December 31.)

Thus, the United Kingdom is unlikely to ever win this award, but could if it submitted a film in Welsh. Indeed, Canada has won this award, for The Barbarian Invasions, a film in French.

Foreign films are eligible for all other Oscars, but only if they meet the Oscars' general eligibility requirements (playing in at least one theater in Los Angeles County for a week within the eligible calendar year). If they don't meet those general requirements, they are ineligible for any further Oscars at future awards.

What is cinematography?

Technically — and to be incredibly pedantic about it — cinematography is the ability to manipulate light to create images within film cameras. But functionally, the award honors much more than that.

A cinematographer is usually known as a "director of photography," and that title may be easier to immediately understand. Within the film industry, cinematography is usually understood to encapsulate everything having to do with the camera — its movement, the images it captures, the light it receives, etc.

That's why several recent cinematography Oscars (awarded to Gravity, Life of Pi, Hugo) have recognized impressive camera feats that, while beautiful, were created in computers. (I don't mean to discount the cinematographers who created those images, but rather to note that said images are often not as "pure" as they might appear. Indeed, some people have suggested splitting the category in two, one for computer-assisted images and one for those without.) The 2015 award went to Birdman, which is all about the restless movement of the camera and appears to take place in one long shot. (Clever edits mask the cuts.)

The cinematographer and director often work closely together to create the images you see onscreen, but the Oscar for cinematography is usually meant to recognize a film's visual beauty or, occasionally, its movement and momentum. In the 1980s and '90s, the award went to films with beautiful exterior landscapes; now, it typically goes to the creation of painterly images within computer-assisted visual effects.

What is film editing?

This one is simple — the film editor takes all of the footage shot and assembles it into the movie you see. He determines the rhythm of individual scenes, decides when you see certain camera angles, and makes the call on what stays in or gets cut.

Like the cinematographer, the film editor also works closely with the director, but instead of doing so on set (as the cinematographer does), he or is present throughout the post-production process. Many directors with long-trusted editors — like, say, Martin Scorsese and editor Thelma Schoonmaker — will have those editors assembling footage into rough cuts even while filming continues.

Ultimately, the decision of final cut rests with the director or studio executives (usually the latter), but the editor is the person with the technical know-how to make that final cut happen. And he often has ideas of his own to contribute to this process.

What is production design?

This category used to be called "Best Art Direction — Set Decoration," and that second term should tip you off as to what it's recognizing. The Production Design Oscar honors the people who create the sets you see in movies.

The production designer (or art director) can be better understood as a "set designer" (even if she doesn't always build the actual sets herself), while the set decorator places props and other items upon those sets to make them come to life. (The award goes to both personnel.) Before it was called Art Direction - Set Decoration, in fact, the category was called "Best Interior Decoration," and that's another good hint as to what's being rewarded here.

Sound mixing and sound editing really are two different things

The Academy, as mentioned, is extra-judicious in what it rewards. So why are there two seemingly interchangeable awards for sound design?

The answer is that they reward two completely different things, weird as that might seem. The award for sound mixing used to be called Best Sound. It rewards the overall soundscape — or soundtrack — of a film. In short, everything you hear in a film must be mixed together and set to certain levels, in accordance with the director's specifications, and that job falls to the sound mixers. That's why Interstellar's nomination in 2015 proved somewhat controversial; the film's dialogue was famously difficult to understand, due to the booming noise from other parts of the soundtrack.

Meanwhile, the Sound Editing category used to be called Sound Effects Editing, and that's a good clue as to what it's for. Many of the sounds you hear in a film must be created by technicians, of course, and this prize goes to the best.

An original song is supposed to be important to the film

The award for Original Song (and original score) is just what it sounds like — music written specifically for a film, rather than for something else. For instance, Jennifer Lawrence's performance of "The Hanging Tree" from the third Hunger Games movie was ineligible, because its lyrics were written by Suzanne Collins for the Hunger Games book series. The music was original, but that's not enough.

Original songs must also be "important" to the film they appear in. They must be heard within the movie itself, or as the first song during the closing credits. And that "important" clause often means that songs by prominent artists are nevertheless snubbed, because they don't play during a major montage or musical number within the film. Indeed, the recent trend in the category has been to move away from songs that play over the closing credits. (That said, most of the 2016 nominees were either opening credits songs or the first song that played over the closing credits.)

A "short film" must be 40 minutes or less

According to the Academy's definition, a short film runs for 40 minutes or less, including credits. This award used to be split into two different categories according to how many reels of film a movie used, with awards for "short subject — one reel" and "short subject — two reel," but those were eventually collapsed into the two awards (for animated and live-action shorts) we have today. (The Documentary Short Subject also has a running time of 40 minutes or less, but that award is administered by the documentary branch of the Academy, rather than its short film branch.)

The three Short Film categories are often the ones suggested for elimination during discussions of how to reduce the running time of the overall Oscars telecast. And to be sure, the fact that the Oscars hand out awards for short films is somewhat archaic. The prizes stem from the days when going to the movies meant seeing a short film or two before the main feature, a practice that rapidly disappeared after with the advent of television.

But short films are still an important way for up-and-coming filmmakers to break into the industry. Indeed, there's a clause in the Academy's regulations for the Short Film categories that allows for award-winning student films to compete. So long as this remains true, these awards are unlikely to go anywhere.