Why do some wounds require stitches and others staples?

Yeah, when me and my sister get bored we come up with some weird stuff. Our father had surgery on his shoulder, where they used stitches, but a friend of mine had some pretty major surgery and they stapled her?
Are there guidelines a doctor goes by in these situations?

Staple are more commonly used on larger incisions in fleshier areas. They hold very well. The shape of the shoulder incision, the size, what it was close to, and the surgeon's preference, may have been the reason to use stitches. But the staples, it's just boom boom boom and you're done. I've had them.

hmm, good one. Maybe it is based on the thickness of the cut/wound.

Sometimes wounds are stiched because the scarring will be less then when using a staple, also the staples are usually used in a large area like major sugury

I giess it depends on the wound and how big it is.

staples are stronger. they are usually put on larger wounds, and wounds that will be under more stress. Usually staples are used on the gut area -- stomach, sides, etc.

Stitches usually on more delicate areas and areas that can be immobilized/not used more easily -- shoulder, arm, leg, hand etc.

yeah I would say you need stiches for deeper wounds - sometimes they use dissolving thread in the deep stiches.
I've heard of them using super glue on some shallower cuts.

Its just the docs. preferance some people dont go back to pa bones to get stiches out , but staples are stonger and require a visit not just for more money but the doc can inspect the wound and make sure its healing right. they both do the same thing its just up to the doc what he feels is best .