Protected Mode and Safe Mode - technical definition

Protected Mode is a modus of operating an Intel Microprocessor in which access control to privileged commands is enabled. Safe Mode is a diagnostic and troubleshooting mode of the Microsoft Windows operating system. Safe Mode skips over the portion of the registry that loads protected-mode device drivers; it also bypasses the Autoexec.bat and Config.sys files. Safe Mode prevents all 32-bit (protected-mode) disk drivers from being loaded except the floppy driver.