Linux system composition

Linux generally has four main parts: Kernel, shell, file system and application. The kernel, shell, and file system form a basic operating system structure, which allows users to run programs, manage files, and use the system. I. Linux kernel is the core of the operating system,...

Linux generally has four main parts: Kernel, shell, file system and application. The kernel, shell, and file system form a basic operating system structure, which allows users to run programs, manage files, and use the system.
I. Linux kernel
The kernel is the core of the operating system and has many basic functions, such as virtual memory, multitasking, shared libraries, demand loading, executable programs, and TCP/IP network functions. Linux kernel modules are divided into the following parts: storage management, CPU and process management, file system, device management and driver, network communication, system initialization and system calling.
 
II. Linux shell
Shell is a system user interface that provides an interface for users to interact with the kernel. It receives user-input commands and sends them to the kernel for execution. it is a command interpreter. In addition, the shell programming language has many features of a common programming language. the shell program written in this programming language has the same effect as other applications.
Currently, the following versions of shell are used.
1. Bourne Shell: developed by Bell Labs.
2. BASH: it is the GNU Bourne Again Shell, which is the default shell on the GNU operating system. most linux release kits use this shell.
3. Korn Shell: it is the development of the Bourne SHell and is compatible with the Bourne Shell in most aspects.
4. C Shell: The BSD version of SUN Shell.
 
III. Linux file system
A file system is an organization for storing files on disks and other storage devices. Linux supports a variety of popular file systems, such as EXT2, EXT3, FAT, FAT32, VFAT, and ISO9660.
 
4. Linux applications
Standard Linux systems generally have a set of assemblies called applications, including text editors, programming languages, X Windows, Office kits, Internet tools, and databases.

Author: "Daily Yunhui"