[Nexus S General] flodb113:
Introduction:

Please read and try to do some research instead of bombarding the developers with the same questions over and over, cluttering the threads with useless and recursive information. I will try to include terms for all the ROMs and Kernels in the Development Section, and remove the obvious things as much as possible. That doesn’t mean it will be perfect! I hope this will be useful for beginners, because it provides most of the basic information you need to get started. From now on, it’s up to you what you do.

I am fully aware that the information included here is for one time use, enough to get you started. Some of these things ARE well known by many of you, but they are still useful for others that are just beginning to learn about their NS. Besides definitions and explanations, I’ll also link to useful posts around xda and other sites, which provide further information on the respective subject.

ROMs​

(ROM: a firmware that contains the Android operating system, and at least critical apps necessary for running your phone (but usually more apps than just those); can be stock or custom, and comes packaged in a *.zip file, flashable under recovery)

Once we decide for a type or ROM (except stock), we head over to the ROMs thread and begin reading the list of features. Now would be a good time to PANIC! No, no, just kidding;) Those words do exist in some kind of language (not necessarily English). So here’s a

very basic

list of the most common terms found in our ROM threads:

[B]AOSP[/B]
[quote]Short for [url=http://source.android.com/]Android Open Source Project[/url]. Its purpose is to maintain the development
of the Android platform. Anyone can use the Android source code for
any purpose, and this is when custom ROMs come in. The [AOSP]
tag is used here to signal a ROM built from Google’s source, a pure
ROM, free of bloatware, with very good performance (generally)
and a very extended degree of customization. [/quote]

[B]Build.prop[/B]
[quote]This file is located in /system/build.prop. It holds the majority
of the runtime flags that are used when Android boots. Basically, it
lists specific information about your device, for applications to use.
You can also edit lines, with a file manager that has access to
/system, in order to change LCD density, build number, device
model and many more. [/quote]

[B]Busybox(ed)[/B]
[quote]Busybox is a collection of simple, but powerful Linux
utilities, that Android doesn't come with by default. It is used
by applications like MetaMorph and Titanium backup in order
to do special operations. You can manage ther version installed
on your phone with various apps from the [url=https://market.android.com/search?q=busybox&c=apps]market[/url] [/quote]

[B]/boot partition[/B]
[quote]This partition includes the bootloader and kernel, and
it enables the phone to boot. Wiping it must be done only if
requested, and the phone must not be rebooted after this operation.
Instalation of a new one is done by flashing a ROM that includes
the /boot partition. [/quote]

[B]/cache partition[/B]
[quote]Inside this partition, Android stores frequently accessed
data and app components. Performing a wipe of the /cache does
not affect personal settings or files, but simply gets rid of existing
data there, which gets automatically rebuilt in time. [/quote]

[B]Dalvik cache[/B]
[quote]Dalvik cache collects the information about the installed
applications and frameworks, and organizes them into a writeable
cache. Under this writeable cache, it stores the “optimized”
bytecode of the applications which is used by the applications
themselves later for a smoother operation. This dalvik cache can
grow as more applications are installed on your phone. It is safe
to wipe dalvik-cache. It will be rebuilt again when the phone
boots. This also explains why your phone takes ages to start up
for the first time. [/quote]

[B]/data partition[/B]
[quote]Also called userdata, the data partition contains the user’s
data – this is where your contacts, messages, settings and apps
that you have installed go. Wiping this partition essentially performs
a factory reset on your device, restoring it to the way it was
when you first booted it, or the way it was after the last official
or custom ROM installation. When you perform a wipe data/factory
reset from recovery, it is this partition that you are wiping. [/quote]

[B]Deodex(ed)[/B]
[quote]In Android file system, applications come in packages with
the extension .apk. These application packages, or APKs contain
certain .odex files whose supposed function is to save space.
These ‘odex’ files are actually collections of parts of an application
that are optimized before booting. Doing so speeds up the boot
process, as it preloads part of an application. Deodexing is basically
repackaging of these APKs in a certain way, such that they are
reassembled into classes.dex files. By doing that, all pieces of an
application package are put together back in one place, thus
eliminating the worry of a modified APK conflicting with some
separate odexed parts. The advantage of deodexing is in modification possibilities. On the other hand, since the .odex files were supposed
to quickly build the dalvik cache, removing them would mean
longer initial boot times. However, this is true only for the first
ever boot after deodexing, since the cache would still get built
over time as applications are used. [/quote]

[B]EFS folder[/B]
[quote]This is a VERY important folder. It contains phone-specific
information, like IMEI (encrypted in the nv_data.bin), wireless
devices MAC addresses, product code (also in the nv_data.bin)
and more. I advise you to make a backup of this folder, and keep
it safe. Remember, backup BEFORE flashing anything. Use [url=http://xdaforums.com/showthread.php?t=1138873]this tool from forum member Borky_16[/url]. [/quote]

[B]Init.d[/B]
[quote]Init.d is very useful because it runs scripts that you can
just delete or replace in the /system/etc/init.d folder. The scripts
are also very flexible and can be used to call other scripts or set
a variety of system settings. [/quote]

[B]G-apps/Gapps[/B]
[quote]A long time ago, in a galaxy far far away, there was a
developer. And he used the Force for developing something called
CyanogenMod. For the happiness of the other folks in the galaxy,
he included some applications from Google. But the Emperor…
oh, sorry… But Google didn’t agree with him including these
proprietary apps, so they sent him a cease and desist letter.
Long story short, the Google Applications are provided separately
via a flashable .zip file. This is the case for pure AOSP ROMs,
and theoretically this is how it should be done. Theoretically. [/quote]

[B]Host File[/B]
[quote]Located in the /etc/ folder, it is used to block ads.
Most ROMs come with a “blocks ~95% of ads” statement. You
can also manage it with apps from the [url=https://market.android.com/search?q=ad+block&c=apps]market[/url]. [/quote]

[B]Logcat[/B]
[quote]The Android logging system provides a mechanism for
collecting and viewing system debug output. Logs from various
applications and portions of the system are collected in a series
of circular buffers, which then can be viewed and filtered by
the logcat command. You can use logcat from an ADB shell to view
the log messages.[/quote]

[B]NANDroid[/B]
[quote]When you take NANDroid backup, it means you are
backing up entire ROM. It’s basically a picture of the ROMs’
state . So when something goes wrong, you have the
chance to restore your phone to the backup state using the NANDroid. [/quote]

[B]NSTools[/B]
[quote]An essential tool that manages tweaks like BLN,
BLD, BLX, Liveoc, OC, CPU Governor, Deep idle and so on.
Written by arifhn, available in the [url=https://market.android.com/details?id=mobi.cyann.nstools&feature=search_result#?t=W251bGwsMSwyLDEsIm1vYmkuY3lhbm4ubnN0b29scyJd]market[/url] and on [url=http://xdaforums.com/showthread.php?t=1333696]xda[/url],
this is a must have application for managing these various options. [/quote]

[B]Odex[/B]
[quote]These ‘odex’ files are actually collections of parts
of an application that are optimized before booting. Also explained at deodex(ed). [/quote]

[B]Power Menu[/B]
[quote]A multiple choice menu that appears when long pressing
the power button. In stock, these are critical options,
such as powering down the device. Developers have also
added options for taking snapshots,
rebooting normally/into bootloader/into recovery and so on. [/quote]

[B]Radio[/B]
[quote]The radio controls basic low-level functions like
network connectivity, Wi-Fi, and GPS. It comes as a radio.img file,
and generally, developers try to leave this out of their
ROMs because different areas require different radios. Pay attention
to this when choosing to flash a new ROM. There is a reference
thread with all the radios [url=http://xdaforums.com/showthread.php?t=1116884]HERE[/url]. [/quote]

[B]Ramdisk[/B]
[quote]Ramdisk.img is a small partition image that is mounted
read-only by the kernel at boot time. It only contains /init
and a few config files. It is used to start init, which will
mount the rest of the system images properly and run the
init procedure. A Ramdisk is a standard Linux feature. [/quote]

[B]Recovery[/B]
[quote]Recovery mode in Android provides an environment for
users to wipe cache, data, factory reset the phone or update
it with a .zip file. There are custom recoveries like [url=http://www.clockworkmod.com/rommanager]ClockworkMod[/url] or [url=http://xdaforums.com/showthread.php?t=1399565]TWRP[/url], which provide additional functionality,
and are very popular for this reason. [/quote]

[B]RTL[/B]
[quote]Short for Right-to-Left and refers to support for languages requiring this type of writing. [/quote]

[B]SetCPU[/B]
[quote]An application built by coolbho3000, which allows CPU speed tweaking and management, allows overclocking, and sets CPU governors. Available on [url=http://xdaforums.com/showthread.php?t=505419]xda[/url] and the [url=https://market.android.com/details?id=com.mhuang.overclocking&feature=search_result#?t=W251bGwsMSwyLDEsImNvbS5taHVhbmcub3ZlcmNsb2NraW5nIl0.]market[/url] (try to buy from the market if you want to support his work). [/quote]

[B]SIM Toolkit (STK)[/B]
[quote]Now if you live in the States, you might not even know what
the STK is, so a bit of explaining is in order. Put simply, the STK
allows carriers to load a simple set of menus and 'applications' on
your SIM card. Earlier versions of Android, up to 1.6, actually
included a rather rough, but functional Sim Toolkit application, but
at some point it was dropped. [/quote]

[B]/system Partition[/B]
[quote]This partition basically contains the entire operating system,
except the kernel and the bootloader. This includes the Android
user interface as well as all the system applications that come
pre-installed on the device. Wiping this partition will remove Android
from the device without rendering it unbootable, and you will
still be able to put the phone into recovery or bootloader mode
to install a new ROM. [/quote]

[B]Unsecured Boot.img[/B]
[quote]Used for adb remount, gets you root by default on a shell. (ro.secure=0) [/quote]

[B]V6 Supercharger Script[/B]
[quote]A more technical explanation could be done here, but
the bottom line is that this is used to make your phone run
faster, by better management of memory. [/quote]

[B]Zipaling[/B]
[quote]Zipalign is an archive alignment tool introduced first
time with 1.6 Android SDK (software development kit). It
optimizes the way an Android application package (APK) is
packaged. Doing so enables the Android operating system to
interact with the application more efficiently, and hence has
the potential to make the application and overall the whole
system much faster. Execution time is minimized for zipaligned
applications, resulting is lesser amount of RAM consumption
when running the APK. [/quote]