[Nexus 7 Q&A, Help & Troubleshooting] GedBlake:
Hi, again AnAndroidUser...

These terms are commonplace amongst people who modify and tinker with their Nexus devices. Like any field of study, it has its own jargon and acronyms.

The following isn't an exhaustive glossary of terms... just some pointers, really:).

The bootloader...

...is the first thing you see when you turn on your Nexus 7 from 'cold'.

Yep. That 'white-on-black' Google Logo IS the bootloader. As also is the 'white-on-black' battery charging animation, when charging with the device fully shut down. For the most part, the bootloader is something that people see... but don't recognize it's importance. It's passive. To fully interact with the bootloader directly, requires that you boot the device as follows...

...from a fully shutdown state...

...press and hold VOL DOWN...

...whilst holding VOL DOWN, press POWER ON...

The N7 should now boot into the bootloader directly... and which is characterised by A GREEN ANDROID lying on it's back, and some text in a tiny font on the lower left hand side of the screen. This text displays, (amongst other things), the bootloader LOCK STATE, the bootloader version (the latest of which is v4.23). In the upper right hand side, will be the word START. This is actually part of a very rudimentary menu/selection scheme. Using the VOL Up or VOL Down buttons, you can cycle through these options...

START>RESTART BOOTLOADER>RECOVERY MODE>POWER OFF>START

...and with the POWER BUTTON to select a given option.

From here in the bootloader, and with the N7 hooked up to a PC via USB, you can now run FASTBOOT commands (you'll need the Android SDK for this), in a command prompt window. The first and most significant command will be...

fastboot oem unlock

This 'unlocks' the bootloader... and allows subsequent fastboot flashing.

The 'white-on-black' Google Logo will now have an 'unlocked padlock' symbol at the bottom of the screen, at boot... signifying that the bootloader is unlocked.

**** WARNING - UNLOCKING THE BOOTLOADER WILL PERFORM A FACTORY RESET, AND WILL

COMPLETELY WIPE THE DEVICE.

ALL USER INSTALLED APPS WILL BE LOST, AS WILL ANY CONTENT - DOCUMENTS, IMAGES, MUSIC FILES, VIDEO FILES YOU MAY HAVE ACQUIRED. THE NEXUS 7 WILL BE AS IT WAS WHEN FIRST UNBOXED. REQUIRING THE RE-SETTING UP OF YOUR WIFI KEY AND RE-ENTERING YOUR GOOGLE ACCOUNT/PLAYSTORE DETAILS ****

CWM and TWRP...

ClockWorkMod and TeamWinRecoveryProject... are both CUSTOM RECOVERIES.

With stock, unmodified Android, you already have a recovery... but it's very limited in it's capabilities. It's really only ever used to update your currently installed version of Android, when OTA updates from Google become available.

Custom Recoveries however, such as CWM or TWRP, are significant enhancements upon the stock recovery.

With CWM or TWRP, you can...

** Root the device...

** Flash a Custom ROM..

** Flash a Custom Kernel...

** Perform a NANDROID backup of your entire system, as it currently stands...

** Perform a NANDROID restore of your last known 'good' working setup...

(--- think of Nandroids, as a bit like 'restore points', in Windows ---).

A Custom Recovery is fastboot flashed with this syntax...

fastboot flash recovery [name-of-recovery-file.img]

Once a Custom Recovery is successfully installed, you can then use it to flash the latest SuperSU root package from Chainfire... which coincidentally has just recently been updated to v1.93. Here is the link...

http://download.chainfire.eu/382/SuperSU/UPDATE-SuperSU-v1.93.zip

Download directly to your N7 and flash in CWM or TWRP.

---------------------------

Finally, and in conclusion... read the 'stickies' about fastboot. Fastboot is key to modifying your Nexus 7... and is also extremely useful to know when flashing an official Google Factory stock image.

Hope this general overview helps...

Rgrds,

Ged.