alright .. thanks for replying !!
I will summarize what I understood from the previous links :
wipe out every thing u have on the RAM (OS & and any application u r running ) and store them to HDD and turn ur pc off without going through the normal turn off procedure.
its turn off ur PC so there is no any power consumption.
not really sure , but I will try : use a a lot of HDD space " I saw on my laptop that this feature uses 11.9 GB !! " . In addition, slower load than Sleep mode. And might a system crash after loading ?!
>when to use ? :
when u want save ur work and u aint going to use the PC for several hours.
ur PC is almost off ! ACPI keep ur RAM powered so it can keep all ur work on as long as it on the sleep mode.
Faster load ! as soon as u open the laptop lid , every thing back same as u left them last time !
ur battery in use ! and I understood that it reduces the battery life. And it does not effect the RAM.
>when to use ?:
if u r going continue ur work within few minutes (not taking long time)
ok .. am I right ? correct my information if there is any thing wrong !