Overview of Linux Operating System

Linux is a popular version of the UNIX operating system known for being open-source, freely available, and designed with UNIX compatibility in mind. Here's a simplified overview of its components and architecture:

Components of Linux System

1. Kernel:

• The core of Linux responsible for managing hardware resources and providing essential services.

• Interacts directly with hardware, handling tasks like process scheduling, memory management, and device drivers.

• Offers a layer of abstraction to hide hardware complexities from applications.

1. System Library:

• Provides functions and utilities that application programs use to access kernel features.

• Implements many operating system functionalities without needing direct access to kernel code.

• Facilitates interaction between applications and the kernel.

1. System Utility:

• Specialized programs responsible for performing individual tasks or managing system-level operations.

• Examples include file management tools, system administration utilities, and networking tools.

Kernel Mode vs User Mode

• Kernel Mode:

• Executes privileged code with full access to system resources.

• Runs in a single process with direct hardware access, ensuring efficiency and speed.

• Provides system services and manages hardware access for user processes.

• User Mode:

• Executes user applications and non-privileged system processes.

• Has limited access to hardware and kernel-level functionalities.

• Relies on system libraries to interface with kernel functions for performing low-level tasks.

Basic Features

• Portability: Linux supports installation on various hardware platforms, ensuring software compatibility across different systems.

• Open Source: Source code is freely available and community-driven, allowing continuous improvement and customization.

• Multi-User: Supports multiple users accessing system resources concurrently, with built-in security features for user authentication.

• Multiprogramming: Enables multiple applications to run simultaneously, utilizing system resources efficiently.

• Hierarchical File System: Organizes files into a standard directory structure, simplifying storage and access management.

• Shell: Provides a command-line interface for users to interact with the kernel and execute system commands or applications.

• Security: Implements user security through features like password protection, file permissions, and data encryption.

Architecture

• Hardware Layer: Includes all physical devices connected to the system.

• Kernel: Interacts directly with hardware, manages system resources, and provides services to higher-level components.

• Shell: Acts as an interface between users and the kernel, interpreting commands and invoking kernel functions.

• Utilities: Collection of programs that extend the operating system's capabilities, performing various system tasks and functions.

Linux's architecture and design principles emphasize stability, performance, and flexibility, making it a widely adopted choice for both server and desktop environments.