What Is Linux?
A free, open-source operating system based on Unix, Linux offers strong security and flexibility. It is used by a variety of endpoint devices like personal computers and smartphones, as well as servers for web hosting and cloud services. It is also popular in a wide range of network devices including routers and firewalls. Linux is also a powerful development platform that can be easily changed to suit specific hardware and software needs.
Linux was developed in 1991 by Linus Torvalds as a student at the University of Helsinki. He began with a simple terminal emulator to connect to larger Unix systems, and then added a kernel, which managed all system input and output. He split the kernel into two sections: kernel space and user space, which manage low-level tasks and allow a user to access information about hardware and software.
The Linux file system is responsible for how files are stored on a hard disk drive (HDD) or solid-state drive (SSD). Linux supports various types of file systems, including the Extended File System and ext4.
An important part of Linux is the init system, which controls how the operating system is started, stopped, and restarted when a computer is turned on or off. The init system uses scripts in the /etc/init.d directory to start, stop, and restart services sequentially based on runlevels. The chmod command is an example of a vital Linux functionality that allows users to change permissions on files, directories, and other resources. Linux classifies permissions into three categories: read, write, and execute. Only those with execute permission can run a program, for instance.
Linux has a large community that provides support and updates for the operating system. Its modularity makes it possible to monitor every aspect of the operating system, giving administrators granular control over user access and application permissions. In addition, the SELinux component of Linux has been in place since 2003, allowing administrators to add a layer of security that protects the kernel and applications from attackers.
Unlike macOS and Windows, which require a license to use, linux is released under the GNU General Public License and can be used, studied, modified, and redistributed as long as the original source code is retained. Combined with its robust feature set, these factors make linux an ideal choice for individuals and businesses looking to cut costs and maximize performance.
Generally, a Linux installation will include an X Window System server for displaying GUI applications on a display. Alternatively, a user may utilize a text-based shell to interact with the operating system. A typical Linux distribution includes a range of software for users to download and install, from desktop tools and programming languages to multiuser business suites. Almost all of the software included with a Linux distribution is freely available, though some of it, such as binary blobs needed to support proprietary hardware drivers, requires a paid license.
