Android Architecture

 Android Architecture is like the structure or layers that make Android work.

It has 4 main layers, each with its own job.

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✅ 1️⃣ Linux Kernel

• Base layer of Android.

• Built on the Linux operating system.

• Handles:
  ✔️ Hardware drivers (camera, display)
  ✔️ Process management
  ✔️ Memory management
  ✔️ Security (permissions)

⭐ Easy to remember: “Linux Kernel talks to hardware.”

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✅ 2️⃣ Hardware Abstraction Layer (HAL)

• Interface between hardware and Android system.

• HAL lets Android use different hardware without changing app code.

• Example: Camera HAL, Audio HAL.

⭐ Easy to remember: “HAL = Translator between hardware and system.”

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✅ 3️⃣ Android Runtime (ART) & Core Libraries

• Runs apps on the device.

• ART = Android Runtime:
  ✔️ Converts app code into machine code.
  ✔️ Runs each app in its own sandbox for security.

• Core Libraries:
  ✔️ Java/Kotlin libraries for app development.
  ✔️ Tools for data structures, networking, graphics.

⭐ Easy to remember: “ART runs your app.”

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✅ 4️⃣ Application Framework

• Provides tools for developers.

• Built-in APIs to create apps.

• Includes:
  ✔️ Activity Manager
  ✔️ Fragment Manager
  ✔️ View System (UI)
  ✔️ Notification Manager
  ✔️ Content Providers
  ✔️ Resource Manager

⭐ Easy to remember: “Framework = developer’s toolkit.”

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✅ 5️⃣ Applications

• Top layer (what users see).

• Pre-installed apps: Phone, Contacts, Settings.

• User-installed apps: WhatsApp, YouTube.

⭐ Easy to remember: “Apps = What you use.”

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✅ 📌 Short Summary to Remember

⭐ Linux Kernel → Talks to hardware.
⭐ HAL → Bridges hardware and system.
⭐ ART & Core Libraries → Runs apps.
⭐ Framework → Developer tools.
⭐ Applications → What users use.

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✅ 📌 📜 Diagram 

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|   Applications         |
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| Application Framework  |
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| Android Runtime (ART)  |
| Core Libraries         |
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| Hardware Abstraction   |
| Layer (HAL)            |
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| Linux Kernel           |
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