windows xp standby, sleep, sleep!

For purposes of windows xp standby, sleep, sleep these three functions have all-you? In a lot of online information, but do not have a good sum, on windows xp, for me, please give us a good explanation of the three functions! ! Thank! ! ! ! ! ! ! Other operating systems can talk about it all the more perfect! ! ! ! Satisfaction, plus 20 points! Give 5 points!

is a function of the three,

standby:turn off the display, the current deal with the information Preservation program in memory

sleep is the entire computer is shut down, including motherboards, monitors, it is to deal with the current procedures for temporary storage of information in the hard disks of a regional

and sleep, In fact, this function with the almost dormant, are handled by the current procedures for temporary storage of information in the hard disks of a regional