WHAT IS LINUX?
Linux is the operating system (OS) used for your Raspberry Pi. Its role is exactly the same as Windows, Mac OS X, Android (in fact, Android is based on a Linux kernel), iOS or any other OS you care to mention. That role is to provide a platform for everything else to run on. It talks to the hardware and it talks to you, the user. But what makes Linux different to any other OS out there? Well, for a start it’s free (more about that later), immensely powerful, highly customisable and the best bit is it’s been created for users by users. However to call Linux ‘an operating system’ is a bit of an understatement. It’s not ‘one operating system’ in the same way that Windows 8 or Mac OS X is. No, it’s many operating systems… hundreds even! As we’ll talk about in the next section, Linux consists of different components, each of which has many different variants. These have all been wrapped into easy-to install distributions to meet different needs. Want a simple desktop replacement? There’s a Linux distribution for that. Want a home media server? There’s a distribution for that too. If you can think of it, someone in the Linux community is probably already developing for it.
HOW IT WORKS
One of the great things about Linux (apart from it being free) is just how customisable it is. Let’s take a look at the main components that make up a Linux install (there are more, but these are the ones you’ll meet most often along your way):
The kernel: The brains of the operation. It talks to the hardware and can be compiled to run on different CPUs, such as the ARM one in the Pi. Any application you run that needs access to hardware – such as keyboard input, monitor output or access to the hard drive – will have to go through the kernel.
The shell: A good old-fashioned command-line interface. There’s nothing you can’t do here, from installing software to viewing system resources and scripting common tasks. It can look daunting at first, but you’ll soon realize it’s not so scary.
Desktop environment: Of course it’s no fun just looking at text all day. This is where the desktop environment comes in and what makes it look like an operating system you’re probably more used to. However, unlike most OSs, you’re not limited to one desktop: you can mix and match and get exactly the look and feel you want.
Applications: Not part of the OS as such, but a key part of any Linux installation. Whether it’s an office suite or a media player, you’ll find it for Linux.