Linux Architecture

Linux is a popular open-source operating system used in servers, desktops, mobile devices, and embedded systems. It is based on the Unix architecture and provides a stable, secure, and flexible platform for various computing needs. To understand how Linux works, it is important to know its architecture — the building blocks that make up the system.

Linux follows a layered architecture. Its architecture is designed in layers, allowing different components to work together efficiently while maintaining stability and security.

 

At the core lies the kernel, which communicates directly with the hardware. Surrounding the kernel are various components and services that allow users and applications to interact with the system.

Linux Architecture Overview

Linux follows a modular design, split into the Kernel (core component), Hardware Layer, System Libraries, and User Applications. The kernel interacts directly with hardware, while user-space tools and applications rely on libraries and services to function. These include the boot-loader, init system, daemons, and shell.

BootLoader

The BootLoader is the first software that runs when a computer starts. It is responsible for loading the Linux kernel into memory and starting it. Popular boot-loaders include GRUB (GRand Unified Boot-loader) and LILO. Without the boot-loader, the system cannot start. Without a BootLoader, the system wouldn’t know how to initialize the OS.

Init System

The Init System is the first process started by the kernel. After the kernel boots, the Init System takes charge as the first process (PID 1). It manages system startup, initializes services, mounts filesystems, and manages system states, initializes hardware, and starts essential background services. Modern Linux systems often use systemd as the init system, replacing older systems like SysVinit.

Daemons

Daemons are background services that start at boot or on-demand and perform various tasks like printing, networking, and system logging. Daemons are background services that run without user interaction. They handle tasks like scheduling (cron), printing (cupsd), or network connections (sshd). They usually start during boot and stay active.

Shell

The Shell is a command-line interface (CLI) that allows users to interact with the system by typing commands. It interprets user input and communicates with the kernel. Popular shells like Bash (Bourne Again Shell) or Zsh interpret commands, run programs, and automate tasks. It acts as a bridge between users and the kernel.