Vardy Adam. - Linux For Beginners: The Ultimate Guide To The Linux Operating System & Linux

The first thing that we need to talk about in this book is about the origins of the Linux. In a nutshell, Linux is an operating system. For those of you who do not know what an operating system is, and for all of you who think you do but may have forgotten what an operating system is, it is actually the software layer that is between your hardware and the software that allows you to get something productive done on a computer.

The operating system is what allows the software to talk to the hardware. It is the one that lets you store information on hard drives, send out print jobs to printers, etc. If you are in a normal Windows environmenta Microsoft Windows Operating systemyou have your hardware at the bottom, you have the Windows operating system on top of that, and then you have Microsoft Office, for example, that sits on top of the operating system.

Linux is an operating system that acts as an intermediaryi.e. a bridgebetween the physical device and the instructional code of a program. The main thing that you just need to realize is that in the Linux world, the software that you will be running is of a completely different type, compared to the ones that you would run in the Windows operating system. Desktop applications like Microsoft Office and Adobe Photoshop are not usually run on a Linux environment. Linux normally runs serversApache web servers, database servers, web virtualization servers, etc.

However, there are various Linux distributions out there that are specifically made for personal desktop computers. These Linux distributions are, in a way, similar to Windows and Mac OS, in a sense that they run the same types of programs like Word Processing programs, photo and video editing programs, web browsing applications, program development applications, games, etc. These Linux distributions are more targeted to home users who just want a free operating system alternative.

Linux did not begin as an operating system, however. Linux was a kernel created by Linus Torvalds while he was a student at the University of Helsinki. The Kernel is essential, but by itself, it is useless. It can only function in the context of a complete operating system. The Linux Kernel was used in combination with the GNU operating system. Imagine GNU as a big complex puzzle with a big piece in the middle missingthe big piece being the Linux Kernel. The complete puzzle equates to a functional operating system.

It is important to understand what a Kernel is as this is the defining component of Linux. A Kernel is the central part of an operating system that is responsible for interfacing all you applications down to the physical hardware.

There are two major types of Kernels competing in today's marketWindows and Unix-like Kernels. The Linux Kernel falls under the latter as does BSD, Mac OS, and Solaris. The term "Unix-like" refers to the fact that they operate similar to, or are based on the original Bell Labs UNIX operating system.

Kernels tend to fall under three categories:

• Micro Kernel A Micro Kernel only manages what it has to: CPU, Memory, and IPC or inter-process communications. If it is not an IPC, Memory, or CPU, it is automatically regarded as an accessory and can be handled in user mode.

• Monolithic Monolithic Kernels like Linux are the opposite of Micro Kernels. They encompass not only the CPU, Memory, and inter-process communications, but other things such as device drivers, file system management, and system server calls.

• Hybrid The Windows Kernel falls under Hybrid because it has the ability to pick and choose what to run in both user and supervisor mode.

And so, between 1991 and 1994, Linus Torvalds created the Linux operating system by combining the GNU OS with the Linux Kernel. Basically, Linus Torvalds wanted an operating system that is not only free, but also something that he can customize to fit according to his programming needs. Linux was his creative little pet project that he did on the side. The big thing with Linux is, because it has an "ux" suffix, and because most of the commands that you use look a lot like UNIX commands, people think that Linux is a type of UNIX operating system. This is totally not the case. UNIX is its own type of operating system. Linux is its own type of operating system.

Linus Torvalds created the entire Linux operating system from the ground up. The reason he created Linux was that he wanted to create an open source operating system for people to use. Back in the day, UNIX was not open source. If you wanted to use UNIX, you had to pay somebody in order to use UNIX. Microsoft Windows, of course, is Microsoft Windows. You always have to pay in order to use Microsoft Windows.