I'm assuming that you are talking about hibernate & stand by feature of Windows XP Operating System 😁

Hibernate Mode:
'Hibernate' feature was introduced in Windows XP. This feature allows you to dump all the contents of RAM (Random Access Memory) to the root directory of your hard disk. You can then switch off the machine. When restarted, Windows reloads the data.

Note that you'll need enough disk space (equal to the size of RAM) for this feature to work.


Stand by:
Popularly known as 'sleep' mode. In 'Stand by' mode, Windows OS turns off non-essential hardware resouces such as hard disk, removable disks, monitor. This enables the system to reactivate quickly when user presses a key or opeartes the mouse. Note that you cannot power-off the system in 'Stand by' mode. This feature is used when the computer idle.

I hope this answers your question 😁

-The Big K-

One more difference -

In Standby, the laptop/desktop requires power to be in the mode.
In Hibernate, once the machine is in that mode, it does not need any power.

In standby mode, the memory isn't written to root. Apparently, depending on the settings in the computer the user has the ability to turn of power consuming devices such as the hard disk, the display, GPU (Graphics Processing Unit ), NIC, wireless radios (bluetooth, wireless NIC ) and such devices. But whatever is in memory is still retained.

That is why, the computer is wakes up fairly quickly from a standby mode, compared to hibernate mode. if the computer is switched off, then the boot time is even longer. The only disadvantage of the standby mode is that very less power is consumed in this mode.