Sleep mode or hibernation?

[cool11]

I would like to know the difference of hibernation and sleep mode on mac os x. I use macbook pro.

Which one makes mac to completely turn off electricity from mac circuits along with keeping an image of current state of osx environment?
A friend of mine told me that sleep mode is not so good to use, because electricity is present inside computer, while hibernation means that computer takes an image of osx state in hard disk, without keeping any power to the circuits, so it is preferable. My friend spoke with pc experience in mind, but I think that it should not be a different thing on macs.
Is there hibernation option in osx? Is it safer/healthier for mac to use such option?
I suppose that the less hours a machine is running, the better it is.

 

[jackeill]

By definition, sleep keeps the RAM memory alive with a little voltage, the rest of the machine is powered down. Hibernation saves the image of RAM on HDD. First one is faster, but uses a little power (about 1% of battery per hour). Second is slower (writing to/reading from disk), but you can easily remove the battery.

OS X doesn't give you an option to choose hibernation or sleep - it always dumps RAM to disk for safety, but keeps it alive also with little power. If you want to control it, you have to use some third-party app like SmartSleep.