Android architecture and mobile OS features
Android is a Linux-based open-source operating system designed primarily for mobile devices. Its architecture consists of several layers: 1) Linux kernel - Provides hardware abstraction, security, and core OS services. 2) Hardware Abstraction Layer (HAL) - Standard interfaces for hardware vendors. 3) Android Runtime (ART) - Executes and manages application code. 4) Native C/C++ libraries - For performance-critical components. 5) Java API framework - Provides APIs for app development. 6) System apps - Core applications like phone, contacts, browser. Android uses a unique security model based on Linux permissions and application sandboxing. Each app runs in its own Dalvik VM instance with limited permissions. Key Android features include activity-based application model, intent system for inter-app communication, content providers for data sharing, and services for background operations. Understanding Android architecture is essential for mobile app developers, embedded system engineers, and security researchers working with mobile platforms.