Production Design - What is that ?

The Fountain (2006)

Movies don't really get famous by their production design. 

It's the actor's performance (excellent or awful, or at least their names), maybe the director's name (when he's famous enough), maybe, maybe the soundtrack, or maybe, maybe, maybe a special scene in the film's storyline that catch the average viewer's attention when he or she is choosing a movie for a saturday eve in front of the local theatre.
But most of the people give a damn on the rest of the movie's elements. 

And that rest is actually called the whole visual look of it.
This overall look of the movie contains (for example) all actors' and extras' costumes, every interior and exterior location seen in it, every single object and all things visible in the movie, used or unused by the characters, every kind of food and drinks that you can see, all the furniture, all the wallpapers, all the cars, all bicycles, all helicopters, all boats, motorcycles, airplanes, every kind of weapon, tanks, newspapers, cell phones, computers, tablets, watches, accessories, flowers, trees, grass, houses, apartments, and every corn of dust, rain, snow, dirty or clean windows, playgrounds, stairs, roofs, antennas, streets, freeways, villages, towns, cities, continents, views on earth from outer space, moons, stars, other planets - and - exactly all these things I just named again and again if the movie takes place on different places, different countries, different planets and maybe different universes.

That's what Production Design is all about.

You may think now that the actors' achievement and director who leads them are more essential than all this other crap I mentioned.
Well, sometimes you may be right. But If you want to create a perfect cinematic illusion that supports the characters and the storyline the best way it can, you need a good Production Designer. Someone who takes care about the whole extremely important rest of the project's visual look.

A Production Designer creates the world the movie takes place in.
An artist who realizes the director's vision of that world, which can be concrete or vague. He or she also works together very closely with the director of photography and the head of lighting. 

It's probably one of the most complex tasks, because of its extremely versatile nature.

from the top to the bottom / left to right : Eyes Wide Shut (1999), The Matrix (1999), Rear Window (1954), Minority Report (2002), Concept Art 1 & 2 for Se7en (1995)