The APM definition of Ready only indicates that your computer or device is fully powered on, it does not differentiate between active and idle conditions. Suspended The Suspended state is a computer state which is defined to be the lowest level of power consumption available that preserves operational data and parameters. The system BIOS may place your computer into the suspended state without notification if it detects a situation which requires an immediate response such as the battery entering a critically low power state. When your computer is in the Suspended state, computation will not be performed until normal activity is resumed. Resumption of activity does not occur until signaled by an external event such as a button press, timer alarm, and so on.
Hibernation saves the complete state of the computer and turns off the power.
The computer appears to be off. This is the lowest power sleeping state available and is secure from power outages. When you resume from a hibernated sleep state, the BIOS performs the normal POST, and then reads the hiberfile that was created to save the computer state. The computer returns to the last state it was in before the computer entered hibernation mode. Hibernate mode reduces start time.