Cold Boot - A cold boot is designed to clear all processors states, running programs, and user data. It also drives the hardware reset line to the processor, thereby clearing all system states, including the date and time. This reset should be used to remove the operating system from a "hung" or "frozen" state because of a fatal program or operating system error.
Hard Reset - A hard reset will clear all user-installed settings, applications, and data. This option is equivalent to a factory-reset.