Before we go into deep details on the Flashing and custom ROMs, let's look at the Android architecture (stack) along with common terminology.
An important factor that sets Android apart from most other mobile operating systems is that it's based on an open source platform, allowing anyone to modify most of Android's source code. Ideally, this would mean that if a developer felt Android needed a specific feature or capability, he or she could build it and incorporate it into the OS.

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