Next

Booting a system.
   wikipedia topic : Booting

Intel boot process (hardware) - OS independent
  Cold boot - from power off, power supplied to all circuitry.
    Memory and I/O initialized.

    Cold boots are rough on the electronics of a system.

    Best practice is to wait 30 seconds before restarting turned off machine.
      Allows capacitors to discharge and circuits to cool.

  Soft or warm reboot - ctrl/alt/del.
    Electrical supply to circuitry not interrupted.

    Post not run.
      Also memory and I/O (including PNP) not reinitialized.

     ctrl/alt/del on older ms-os pcs. (os <= win 95)

     reset button or quick push of poweer button on newer oses.

     Linux has kexec, which allows the loading of a new os while power is 
       maintained.
          
     Also, changing runlevels in Linux is a soft-boot.

    Soft re-boot less stress on circuitry.

    But may not clear all circuits if re-boot was done because of system
      problems, such as misbehaving i/o.

Next