Tuesday, 4 March 2008

Why there are all these different versions of Linux

For anyone familiar only with MS Windows who's venturing into the world of Linux there are a confusing number of versions available. Here's some of the reasoning behind this.

An operating system is built of layers of software on top of one another. At the heart of the system is the Kernel. The Kernel is a program that runs all the time managing the system, it manages which programs are allowed to run and when. It also manages access to all the hardware (devices) in the computer for those programs. You as the user never really interact directly with the kernel. Other programs manage your interaction with the computer using the services provided by the kernel. Even on systems without a graphical interface the command console is provided by a separate program called a 'shell'. Further additional layers of software provides the nice graphical windows interface, with all the pointy clicky mouse stuff, for the user and their programs. All this additional software comes in a variety of different flavours and versions with varying degrees of sophistication and resource requirement.

Linux is just the kernel of the operating system, when you install Linux on a PC you install a 'distribution' which has all the other required pieces of software and configuration files included.

Most distributions include a number of the more popular applications in the installation such as text editor, file manager, web browser, paint program, word processor etc.

The software that's initially installed with the distribution will depend on the intended use for the operating system, and the likely preferences of the intended user. Does the system require a graphical interface or just need a text based command shell for a simple application, for instance.

Fortunately for us there are some smart and dedicated people out there who build and manage these Linux distributions, keeping them up to date, and doing all the hard work of configuring the software to work together.

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