What is Android? Introduction to Android OS, Features, Architecture, and Versions

Android is a versatile, Linux-based operating system developed by Android Inc. (2003) and later acquired by Google in 2005. Android OS was introduced in the market almost 17 years ago (23 September 2008), and since then, the software has evolved a lot. Known for its flexibility and open-source nature, Android powers a vast ecosystem of devices, from smartphones and tablets to smart TVs, wearables, and even cars. With over 3 billion active devices globally as of 2025, Android dominates the market share for mobile operating systems, currently around 71-72%. This article explores Android’s definition, key features, origins, architectural design, emulator functionality, and a detailed history of its versions up to the latest Android 16 beta.

What is the Android OS?

Android is an open-source, Linux-based operating system designed primarily for touchscreen devices like smartphones, tablets, and wearables. Built on the Linux kernel, it allows developers worldwide to customize and enhance its functionality, making it highly adaptable across various hardware platforms. Android’s open-source model, governed by the Open Handset Alliance (led by Google), enables manufacturers like Samsung, Xiaomi, and OnePlus to tailor the OS to their devices while integrating Google’s suite of services, such as Gmail, Google Maps, and the Play Store.

Key Characteristics of Android OS:

• Open-Source: Freely accessible for developers to modify and distribute.
• Customizable: Users can personalize home screens, widgets, and themes.
• App Ecosystem: The Google Play Store hosts millions of apps, from productivity tools to games.
• Hardware Flexibility: Supports diverse devices, including budget smartphones and high-end foldables.
• Google Integration: Seamlessly connects with Google services like Drive, Photos, and Assistant.

Why Was Android Created?

Android was initially developed by Android Inc., founded in 2003 by Andy Rubin, Rich Miner, Nick Sears, and Chris White in Palo Alto, California. Originally intended for digital cameras, the team pivoted to smartphones due to the larger market potential. Google acquired Android Inc. in 2005, transforming it into a mobile OS to compete with platforms like Symbian and Windows Mobile. Google’s vision was to create an open-source OS that fosters innovation, supports diverse hardware, and integrates its services, ultimately making smartphones accessible to a global audience.

Key Features of Android OS

Key features include its user-friendly interface, multi-tasking capabilities, and robust connectivity options. Here are some standout features of modern Android versions.

• Gesture Navigation: Smooth, intuitive controls introduced in Android 9 and refined in later versions.
• Material You Design: Dynamic them based on wallpaper colors, introduced in Android 12.
• Privacy Enhancements: One-time permissions, app access history, and data encryption in Android 15.
• Multitasking: Split-screen and picture-in-picture modes for efficient app usage.
• Battery Optimization: Doze Mode (Android 6) and adaptive battery features extend device life.
• Accessibility: Live captions, dark theme, and screen recording improve usability.
• Smart Home Integration: Control devices like lights and cameras from Wear OS smartwatches.
• Security: Google Play Protect scans for malicious apps, with enhanced protections in Android 15

Architectural Design of Android

Android’s architecture is layered and modular, designed to support a wide variety of hardware and use cases. It comprises five main sections across four layers:

Linux Kernel

The foundation of Android, the Linux kernel, manages core functions like memory, process management, and hardware drivers (e.g., for cameras and displays). It provides robust networking and security without requiring direct hardware interfaces.

Hardware Abstraction Layer (HAL)

The HAL enables the kernel to interact with device-specific hardware, ensuring compatibility across diverse manufacturers.

Native Libraries

Built on the kernel, libraries like WebKit (for browsing), OpenGL (for graphics), and SQLite (for databases) support app functionality. These are written in C/C++ for performance.

Android Runtime (ART)

The Android Runtime, featuring the ART (replacing Dalvik since Android 5), executes apps efficiently. ART uses ahead-of-time compilation to improve app performance and supports Linux features like multithreading.

Application Framework and Apps

The top layer includes the application framework (for APIs like notifications and telephony) and user-facing apps (e.g., browser, contacts). Developers build apps using this framework, leveraging Java or Kotlin.

What is an Android Emulator?

An Android Emulator is a virtual device that simulates the Android OS on a computer. It Enable developers to test and debug apps without physical hardware. It replicates a device’s software and hardware features, including UI navigation, sensors, and network access, but does not support phone calls. Emulators use Android Virtual Device (AVD) configurations to mimic specific device profiles, supporting tasks like app development, UI testing, and media playback. Tools like Android Studio provide robust emulator support for developers.

Android Version History: Release Dates and Features

Here is the list of Android versions that have been released by April 2025. A little introduction to the most popular Android versions. Android 15 “Vanilla Ice Cream” is the latest version.

The first commercial version, Android 1.0, was released on September 23, 2008.

Android 1.0 G1 Introduced 2008: Debuted on the HTC Dream (aka T-Mobile G1), Android 1.0 introduced the Android Market with just 35 apps, laying the foundation for Google’s mobile ecosystem.

Android 1.5 Cupcake Introduced 2009: Released in April 2009, Cupcake was the first named Android version. It brought third-party app widgets, an on-screen keyboard, and video recording, sparking Android’s app revolution.

Android 1.6 Donut Introduced 2009: Launched in September 2009, Donut added support for multiple screen sizes and resolutions, plus CDMA network compatibility, broadening Android’s device reach.

Android 2.0-2.1 Eclair Introduced 2009: Released in October 2009, Eclair powered the Motorola Droid, it introduced live wallpapers, Google Maps Navigation, and speech-to-text for a richer user experience.

Android 2.2 Froyo Introduced 2010: Launched in May 2010, Froyo boosted performance with JIT compilation, added Wi-Fi hotspot functionality, and enabled Adobe Flash support in browsers.

Android 2.3 Gingerbread Introduced 2011: Released in February 2011, Gingerbread gave Android its iconic green robot identity, added NFC support, and improved gaming with better graphics.

Android 3.0-3.2 Honeycomb Introduced 2011: Launched in February 2011, Honeycomb was tailored for tablets. It also introduced a holographic UI, enhanced multitasking, and hardware acceleration.

Android 4.0 Ice Cream Sandwich Introduced in 2011: Released in October 2011, Ice Cream Sandwich unified phone and tablet interfaces, added face recognition for unlocking phones, data usage tracking, and live video effects.

Android 4.1-4.3 Jelly Bean Introduced 2012: Launched in June 2012, Jelly Bean’s “Project Butter” delivered smoother performance, expandable notifications, and Google Now for predictive search.

Android 4.4 KitKat Introduced 2013: Released in October 2013, KitKat, in partnership with Nestlé, optimized performance for low-end devices, added “OK, Google” voice commands, and introduced emojis.

Android 5.0-5.1 Lollipop Introduced 2014: Launched in November 2014, Lollipop introduces us to the world of Material Design, lock screen notifications, 64-bit support, and Project Volta for better battery life.

Android 6.0 Marshmallow Introduced in 2015: Released in October 2015, Marshmallow refined Lollipop with Doze Mode, granular app permissions, Google Now on Tap, and fingerprint reader support.

Android 7.0-7.1 Nougat Introduced 2016: Launched in August 2016, Nougat brought split-screen multitasking, bundled notifications, Data Saver, and Daydream VR for immersive experiences.

Android 8.0-8.1 Oreo Introduced 2017: Released in August 2017, Oreo focused on speed and efficiency, adding picture-in-picture mode, notification dots, and background app limits.

Android 9.0 Pie Introduced 2018: Launched in August 2018, Pie introduced gesture navigation, adaptive battery, digital wellbeing tools, and a sleek, modernized UI.

Android 10 (Quince Tart) Introduced in 2019: Released on September 3, 2019, Android 10 introduces dark theme, live captions on videos, Focus Mode, support for biometric authentication, WPA3 Wi-Fi security and more.

Android 11 (Red Velvet Cake) Introduced 2020: Launched on September 8, 2020, Android 11 added screen recording, chat Bubbles, smart device controls, one-time permissions, and dark theme scheduling.

Android 12 (Snow Cone) Introduced 2021: Released in October 2021, Android 12 unveiled Material You theming, a privacy dashboard, revamped widgets, and microphone/camera access indicators.

Android 13 (Tiramisu) Introduced 2022: Launched in August 2022, Tiramisu enhanced the Material You experience with more color options, added improved privacy features like photo picker for safer file access, and enhanced device interoperability with features like cross-device copy and paste.

Android 14 (Upside Down Cake) Introduced in 2023: Released in October 2023, Android 14 improved battery life, added predictive back gestures, enhanced foldable support, and refined privacy features.

Android 15 (Vanilla Ice Cream) Introduced 2024: Launched on October 15, 2024, Android 15 introduced improved AI integration for smarter notifications and app suggestions, enhanced battery health management tools, stronger privacy controls, and expanded support for foldable and large-screen devices.

Android 16 (Baklava) currently in beta as of April 2025: Android 16 emphasizes deeper AI-driven personalization, introduces new security enhancements, improves satellite connectivity for emergency communication, and brings smoother transitions for foldable devices.

What devices use Android operating system?

Android powers a wide range of devices beyond smartphones and tablets, including:

• Wearables: Smartwatches running Wear OS (e.g., Samsung Galaxy Watch).
• Televisions: Smart TVs with Android TV (e.g., Sony Bravia).
• Cars: Android Auto for in-car infotainment.
• E-readers, laptops, and IoT devices: Custom implementations by manufacturers like Amazon and Lenovo.

Android OS vs. Android System

The Android OS refers to the core kernel and low-level components managing hardware interactions, while the Android System encompasses higher-level frameworks, apps, and services (e.g., Google Play Services) that handle app permissions, sensors, and user interactions. The system acts as a bridge between apps and the OS.

Can Android Be Hacked?

Yes, Android devices are vulnerable to hacking, though Google mitigates risks through Google Play Protect, regular security patches, and app sandboxing. Historical vulnerabilities like Stagefright (2015) affected millions of devices, but modern Android versions (e.g., 15) include advanced encryption and permission controls to enhance security.