When you put your computer into hibernation, everything in computer memory is saved on your hard disk. When you turn the computer back on, all programs and documents that were open when you turned the computer off are restored on the desktop.
You might want to save your work before putting your computer on standby. While the computer is on standby, information in computer memory is not saved on your hard disk. If there is an interruption in power, information in memory is lost.
Very subtle difference.