Can someone explain me clearly and also give few example for drama genre films.
My take on it has always been that there's no black and white answer, because Foley crews do a lot on some major union shows that delve into the FX area (like Dan O'Connell creating sounds of a steam train), and sometimes they only do the feet/cloth and such which is termed as 'tradition' Foley.
I've come to call the difference as this: FX adds in the impact, Foley adds the human touch
Traditionally though, Foley crews are always obligated to shoot:
-footsteps BG-cloth pass (including specifics/props like jackets, sweaters, etc) -all prop pickups/putdowns/hand-offs/handling (books, guns, glasses, plates, etc) -hands (touching skin, hands slide on surface, rubs, etc) -human interaction (kissing, sucking, etc) -grabs and pats (cloth and flesh, objects like doors, etc)
And from there they tend to cover props which require the human quality such as stirring coffee with a spoon or doing complicated prop movements like rubbing a cloth repeatedly on a window (although FX sometimes sweetens it with rub squeaks to blend with the Foley). This is where the FX side that's usually cut (if any for some these things) adds the impact especially if something needs to cut through the mix. Sometimes they'll shoot door FX and water sounds too, sometimes punches and crash sequences. It really depends on the stage facility and the show's operating budget. But the above is what is traditionally shot under the most basic of Foley passes. Especially in walk-n-talk drama films where those are most of anything that's happening.
Hope it helps!
The more traditional view is that foley is performed to picture, whereas FX are cut to picture. There is an efficiency idea at work here. To piggy-back off of an example that Stavrosound mentioned, let's use the idea of props handling (specifically a dinner scene). I could, with very little fuss, edit in all of the plate/silverware/glass/chair/table noises for this type of scene with effects from a library. Little fuss, but it's going to take me a while if I have to do it for more than one character. A foley artist can perform all of the necessary sounds for one character (sometimes more) in a single pass through the scene. That's a lot less time than it's going to take me to cut each of those individual sounds by hand.
That's the "traditional" view. Foley artists have been known to help sound designers and editors by performing complex sound sequences that would take far longer to cut by hand...even though they aren't of the human/animal movement and environmental interaction variety. It depends on the budget of the project. Foley has also come into use in describing library sound effects for movement and handling/interaction. Not everyone has the space or budget to hire additional sound crew, such as foley artists. That's why you'll see things like "foley_footstep" sounds in libraries. They have come to be described and named as "foley" sounds, despite the fact that they are not performed, because it is a fast way to locate and identify sounds one might need to cover that specific purpose.
In my opinion, and I follow the old school in this, there is only one difference: performance.
Sound effects are something you can record whenever you want, and normally referred to as sound editing (sound design is in many ways an artistic and philosophical extension to sound editing). It doesn't even matter what you'll use it for later, as it's in the library for whenever called for. It can be anything from extremely complicated explosions in something mechanical to simple footsteps and handclaps, though it's most common to use sound editing for hard effects (gunshots, punches and such) as the better control often outweighs the longer time needed to find, edit and paste every single effect in sync.
Foley is something performed in front of a screen in sync to the movie. It can be anything from simple (or perhaps not so simple, depending on the performer) footsteps and cloth to heavy fist-fights to, I've heard, complete train-stations! It's a MUCH faster way to work, but puts very high demands on the one performing as well as it doesn't have as much control over the final result as pure sound editing.
Because of the different techniques positive as well as negative aspects most movies, with exceptions of course, mostly in exchanging foley with editing due to poor performance expected, combine the two techniques by using them for what they're best suited for: Foley for more personal and dynamic sounds like footsteps, animal movement and cloth, and editing for explosions, impacts, train-stations ;-) and cloth rustling to mane but a few things.
Other things, like the slams of doors, bells and falls are more individual how they're treated. I do all those things as consciously designed edits as that suits med best, and I have friends who would never even consider doing such sounds anyway but foley.
The term "foley" comes from Jack Foley. He did, as far as I know, everything this way and was frigging fantastic at it!
I agree with Stavrosound. The main difference (in my little head) is usually between living and non-living sounds. So, a lightsaber would be a sound effect and the rustling of darth vader's clothes would be foley. However, there is overlap depending on the foley artists/sound designers: some foley artists make the sound of horses from their mouths, some use library material and others will record some (budget permitting usually). As a broad difference that it.
However, a lot of foley sessions will yield incredible opportunities for sound manipulation and design (ie sound effects): eg. in the new transformers they melted dry ice on metal to give a particular metallic ringing sound which was manipulated to be all sorts of twisted mechanical sounds.
Background sound F/X in my experience would be sounds that are related to the scene. In other words, your filming a burning building and people are outside gathering. Of course a fire engine is going to drive and to fill the clip properly, the audio of the sirens have to be enhanced for full effect. In a war film, the explosions and things pertinent to that scene like gun fire will be clearly and and distinctively heard. Two people sitting in the park talking...your focus is on the people, not the birds heard softly chirping, the children at a far distance playing or the soft chatting of people on their cell phone...things that aren't essential to the scene but necessary for a realistic effect.
Anything on screen that is done by a human being is Foley and anything that happens without human action or as a result of Human action is SFX. For example: I put the car key in the ignition, rotate and the car turns on. In this scene, putting in the keys and rotating sound is Foley. But the car turning on sound is Sound Effect (SFX).