: Do not disconnect the cable until the phone reboots and the tool shows "100%" or "Finished". Important Troubleshooting Flashing LG Stock Firmware Guide | PDF - Scribd
: Repairs system files without deleting your personal data.
: Click Start and then OK on the country/language selection window (these settings often don't matter as long as the firmware matches your model).
: A "clean" install that wipes everything. Recommended if you are fixing a major software error or bootloop.
: Flashing can wipe all user data. Back up your files unless you are performing a "Normal Flash" which attempts to keep data.