Definition of Linux:
Linux is an open-source, Unix-like operating system kernel that serves as the core foundation for a wide array of operating systems, commonly known as Linux distributions or distros. Developed by Linus Torvalds in 1991, Linux has grown into a powerful and versatile operating system used across various platforms, including servers, desktops, embedded systems, and mobile devices.
Unlike proprietary operating systems, Linux is distributed under the GNU General Public License (GPL), which grants users the freedom to view, modify, and distribute the source code. This open-source nature has fostered a vibrant community of developers who contribute to its continual improvement and adaptation.
Architecture of Linux:
Kernel:
- At the heart of Linux is the kernel, a monolithic core responsible for managing system resources, providing process and memory management, handling device drivers, and facilitating communication between hardware and software.
Shell:
- The shell is the user interface to the operating system, acting as a command interpreter that allows users to interact with the kernel. It interprets user commands and executes them by calling the necessary programs or system functions.
Application Layer:
- The application layer encompasses user-space programs and utilities that run on top of the kernel. This includes a vast array of software, ranging from command-line tools to graphical user interfaces (GUIs) and desktop environments.
Kernel Space and User Space:
- Linux employs a clear separation between kernel space and user space. Kernel space contains the core operating system functions and device drivers, while user space hosts user applications and processes. This separation enhances system stability and security.
Shell:
- The shell, such as the popular Bash (Bourne Again SHell), is a command-line interpreter that allows users to interact with the kernel and execute commands. It provides a powerful scripting environment and supports features like command history and job control.
Kernel:
- The kernel is the central component that manages system resources, including CPU, memory, devices, and file systems. It facilitates communication between hardware and software, ensuring efficient and secure operation of the entire system.