Linux

Linux is the most popular operating system in the world, that powers almost all the servers and android phones among many other devices that we use day to day. It is very similar to operating systems like Windows and Mac OS. Linus Torvalds built the core of the Linux operating system, known as the kernel. A kernel alone does not make an operating system, but Stallman's GNU tools were from a project to create an operating system as well--a project that was missing a kernel to make Stallman's operating system complete. Torvalds' matching of GNU tools with the Linux kernel marked the beginning of the Linux operating system as it is known today.

What is kernel?

Kernel is the central part of an operating system that is responsible for interfacing all the applications down to the physical hardware. All operating systems have kernels. The linux kernel consists of various important parts : process management, memory management, hardware device drivers, network management and so on. The most important ones are memory and process management which take care of assigning memory areas to processes and creates processes, implements multitasking by switching process on the processor respectively. There are two major kernels in the market today

• Windows
• Unix-like : Linux, BSD, Mac OS, Solaris

The term Unix-like refers to the fact that they are based on or operate similar to the original bell labs Unix operating system.

Kernels tend to fall under 3 categories

• Micro Kernel:

  Only manages CPU, Memory, IPC (Inter Process communication), rest is considered as an accessory and can be handled in user mode.

• Monolithic Kernel:

  Like Linux not only manage CPU, Memory, IPC but also takes care of device drivers, file system management and system server calls.

• Hybrid Kernel:

  Like windows has the ability to choose what to run in both user mode and supervisor mode.

Linux Distributions

Typically Linux is packaged in form called as Linux distribution mainly for desktop and server use. Popular mainstream Linux distributions include debian, ubuntu, mint and fedora. They include Linux kernel supporting utilities, libraries and large number of software (like LibreOffice, firefox) to fulfill the distribution's intended use.

The Linux kernel is released under the GNU general Public license and is a prominent example of free and open source software. Open source community believes in a model of public collaboration and contribution creates better software.

Where is Linux used?

Linux, which began its existence as a server OS has become very useful as a desktop OS also and is being used on mobile phones, flight entertainment systems, ATMs, TVs and so on. Developers around the world are making use of modular feature of Linux in smart watches to supercomputers. So basically,

Linux is simply everywhere.