Blowback/recoil operated

[Desert_Fox_Rommel]

So what exactly is the difference? I hear some automatic arms called "recoil operated" and others "blowback" operated. They sound the same. Is there a difference between the two? If so then what?  

[Stoic Socialist]

Recoil operation is taking advantage of the recoil from the ammunition discharging, and blowback is a variation of gas-operation, taking advantage of the gases from the burning powder.

I think wikipedia gives some pretty good diagrams, so I'll link some.

http://en.wikipedia.org/wiki/Recoil_operation
http://en.wikipedia.org/wiki/Blowback_(arms)

I'd link to howstuff works, but they don't appear to have anything good representing these two.
Good luck.

EDIT:
http://science.howstuffworks.com/machine-gun5.htm
http://science.howstuffworks.com/machine-gun6.htm  

[Desert_Fox_Rommel]

ah ok