Concepts

android kernel

Android Common Kernel: The Android common kernel (ACK) is based on a Linux Long Term Supported (LTS) kernel.
Android System Core: Minimal Linux system. It initializes the device and starts before the Android Runtime (ART) and java-based services or applications.
Generic Kernel Image (GKI) kernel: This kernel has two parts: the core GKI kernel (common across all devices) and GKI modules (by Google) that can be dynamically loaded on devices where applicable.

Android Compatibility Definition Document: The Android Compatibility Definition Document (CDD) enumerates the requirements that must be met in order for devices to be compatible with the latest version of Android.
HAL (Hardware Abstraction Layer) interface definition language: HIDL is used to specify the interface between a HAL (Hardware Abstraction Layer) and its users.
Hardware Abstraction Layer (HAL)
Platform Development Kit: Platform Development Kit. This is a reduced set of an Android release. Its Goal is to help chipset vendors and OEMs to prepare a new Android release. PDK includes the components for Android HAL (Hardware Abstraction Layer) development.
vendor kernel module: A hardware-specific kernel module developed by a partner, that contains SoC and device-specific functionality. A vendor module is a type of dynamically loadable kernel module.
Vendor Native Development Kit (VNDK)
Vendor Test Suite: The Vendor Test Suite (VTS) provides tests to validate the vendor interface between the lower level vendor implementation and the Android OS framework.

Android base framework: The android framework provides API / interfaces / classes on top of which applications are built.
Android recovery: Android recovery has its dedicated partition. It can be used reset, update or recover the Android installation.
Android Runtime (ART): Application runtime environment used by Android. ART compiles applications into native machine code "ahead of time" (AOT) when they are installed.
Android Runtime library: libart implements the core part of Android Runtime (execution environment using mainly AOT compilation, or JIT compilation or interpretation)
dalvik: Dalvik is a virtual machine (VM) for Android applications. Dalvik VM is discontinued, replaced by ART (Android Runtime). Dalvik bytecode format is still used as a distribution format.
rendrescript framework: RenderScript is a framework for running computationally intensive tasks at high performance on Android. The runtime parallelizes work across multi-core CPUs and GPU of the device.

android openjdk library: Android uses OpenJDK java libraries
Android Package file format: The Android Package (APK) file format is used for distribution and installation of android application.
Android Pony EXpress (APEX): The Android Pony EXpress (APEX) container format is used to install / update lower-level system modules.
Android Virtual Devices: An Android Virtual Device (AVD) is a configuration that defines the characteristics of an Android phone, tablet, Wear OS, Android TV, or Automotive OS device that you want to simulate in the Android Emulator.
bionic: C Runtime (CRT) for Android, port of the BSD C library (c-library, math and other core runtime libraries)
Dalvik Executable: Dalvik Executable (DEX) format contains Dalvik virtual machine bytecode.
dex2oat: Dex2oat takes a DEX file with Dalvik bytecode (or APK). Depending on options, it verifies / optimizes / compiles it to native code (Ahead-of-time compilation).
dexter: Android library that simplifies the process of requesting permissions at runtime.
libjavacore: libjavacore is a native library in the Android operating system that provides the interface between the Java virtual machine (JVM) and the underlying Android system.

Android Camera2: The Android Camera application allows users to take photos and videos using the device's camera.
Android Launcher3: The Android Launcher is the user interface that manages the home screen, how to launch mobile apps, make phone calls, etc.
Android Settings: Android Settings application
calendar: calendar application
contacts: contacts application
gallery: gallery application. This is an offline photo gallery. The application allows to browse, view, edit, and manage photos.

Android debug bridge: Android debug bridge (adb) is a command-line tool to communicate with an android device.
AVD launcher: Front-end for the Android Virtual Devices (AVD) emulator.

android mainline project: Project Mainline modularizes android and enables to update core OS components through Google Play. It also relies on Treble project.
gki project: A Google project addressing kernel fragmentation by separating common core kernel functionality from vendor-specific SoC and board support into loadable modules.
treble: Project Treble was a re-architecture of Android that created a split between the OS framework and device-specific low-level software (called the vendor implementation) through a well-defined, stable vendor interface. As a part of this split, the Android OS framework guarantees backward compatibility with the vendor implementation, which is checked through a standardized compliance test suite (VTS).

blueprint: meta-build system (reads Blueprints files, produces a Ninja manifest)
soong: The Android build system. It replaces Android.mk files with Android.bp files, which are JSON-like simple declarative descriptions of modules to build.

Android Compatibility Test Suite: This test suite insures that an Android build complies with the Android specifications.
Android Mainline Test Suite: MTS consists of a set of testing frameworks and test cases, designed to help enhance the robustness, reliability, and compliance of a mainline train (i.e. a set of mainline modules).