A custom ROM
is basically a different operating system for your smartphone / tablet.
Unlike the pre-installed firmware that is provided by the manufacturer,
such as Samsung Touchwiz or HTC Sense, custom ROMs provide an almost
pure Android experience much like that you’d find on Google’s Nexus
devices. Custom ROMS are also enriched with many useful extra features
and customization options that affect the behavior of the system. Thus,
the user gets more control over their device than it would ever be
possible with the standard software from the manufacturer. In addition,
custom ROMs are also a good way to install a more recent version of
Android on your device.
What is a nightly build?
Nightly build are an automatically created version of the custom ROM
that adds the most recent changes into the code base. These fixes,
updates, and new features can be accessed and flashed nightly by those
who want to test them out. However, since they are created automatically
they are not checked for errors or bugs. As such, they are not
recommended to be used for daily use but more-so for error checking and
debugging.
Gapps are basically all the Google Apps. This includes such Google
apps as the Play Store and GMAIL. For legal reasons, these apps are not a
standard part of custom ROMS, but must be installed separately at the
same time as flashing a ROM.
A boot loader is a separate partition on the internal memory of the
smartphone / tablet. The boot loader loads the actual Android operating
system.]
What is a Nandroid backup?
A Nandroid backup is a complete image of your system. Should you do
something, for example delete a necessary system file and softbrick your
device, you can return it to the previous state by restoring a backup
of your system using this.
What is a cache / Dalvik cache?
The cache is a buffer memory and frequently used files are stored
here for faster retrieval. The Dalvik cahce is a directory tree for all
programs.
What is fastboot?
Fastboot is a special tool that is used for diagnostic and
development purposes. To an Android device that is in fastboot mode and
connected to a computer allows you to boot images and other files to
your smartphone. As well, other commands can be sent to the device, such
as telling it to delete certain partitions or go to the bootloader.
A kernel is the link between the hardare and software on your device.
Whenever you interact with your Android smartphone, the kernel sends
the requests made by the software to the hardware and makes the
appropriate changes and vice versa. If you, for example, change the
brightness with the slider on your device, the kernel registers the
change and causes the brightness to actually change on the screen. Of
course, this is a very simplistic explanation of what goes on behind the
scenes, but gives a pretty clear insight into what a kernel does.
A custom kernel can expand the system to include
additional functions, such as changing the CPU clock rates or adjusting
the battery usage and idle times.
Conclusion
And so, those were a bunch of the most common used terms related to
rooting and using a custom ROM and you’ll most likely see them when we
and other talk about the process. There, of course, is much more to
discover and learn, but for now, it’s a nice introduction into what some
of the terms actually mean.