In a nutshell, computer operating systems arrange co-operation and sharing of computer hardware resources, computer software and the user. OS development has had a long history stretching over decades but really was a concept introduced with mainframes ( large computers ).
The general idea is simple enough. The 'system' controls resources required by programs by allocating those resources such as system memory and processor ( CPU - Central Processing Unit ). It also allows programs to access these resources through mechanism of system calls. This in turn allows programs to be much more compact and efficient. The alternative to this would be that every program would have to include code manipulation of all the resources required, a very cumbersome and inefficient alternative.
Most domestic users are not well versed in computing science and simply require their desktop or laptop to work. Without a doubt, the Windows OS by Microsoft is the most well known but, there are in fact many others available to the domestic market such as Mac and Linux. It is an undisputed fact that the Windows OS has had an enormous impact in terms of allowing easy desktop use and manipulation of the home computer by means of the GUI (Graphical User Interface). First introduced as Windows 95, Microsoft very quickly became the domestic market leader and has overall maintained that position although it has lost considerable ground to other systems. This is in complete contrast the professional applications. A startling fact to some would be the revelation that most of the internet is powered by open source software such as the Apache web server and the Linux OS. This in turn has fuelled in part, relatively cheap and reliable web site hosting.
Although Windows 95 when first installed seemed to work well enough, its flaws soon became apparent. These issues would manifest as system freezes and crashes (some will still remember the 'blue screen of death'). Moreover, its vulnerabilities were quickly exposed and exploited to reveal deep seated system vulnerabilities to viruses and worms which were capable of severe damage to the OS and loss of data. Further incarnations attempted to plug these security holes and improve reliability along with numerous service packs and patches. The first evidence of improvement was the introduction of Windows XP, a port of the professional NT OS. Now having passed the Vista debacle the latest and greatest offering from Microsoft (at the time of writing) is Windows 7.
Throughout all the Windows OS upgrades and revisions, the cost has been squarely put on the shoulders of the consumer. The average cost of an new issue has been around 200 € for the cheapest 'domestic' editions and considerably more for the 'professional' editions. There are however, alternatives for the domestic user.
The Linux OS is available in a variety of 'distributions' which offer graphical desktops, rock solid performance and complete immunity from any virus attack which makes web browsing and emailing safe. These systems are available from vendors at very reasonable cost, often less than 50 € if one of the official CD's are purchased (see resources section below). Most vendors make these systems freely available however. All that is required is a high speed internet connection (typical file sizes are around 700Mb) and a program to burn an ISO image onto a CD. It is even possible to incorporate a complete viable system on a USB stick making the system and data completely portable between computers. Now how cool is that!
One Linux distribution which is gaining high popularity Ubuntu. Completely stable and the latest release 9.1 offers a very flexible system incorporating a choice of desktops (Gnome or KDE) and a wide range software already included. Ubuntu also makes upgrading to a new release easy and with the packaging system new software is easily installable and updatable. All this at ZERO cost.
Installation is very easy, just load the prepared CD and configure the computer BIOS to boot from CD and follow
the easy on screen instructions. For the experimenter who is not really sure if Linux will suite his requirements
The CD is of the 'live CD' variety which allows a try out of the system. Any changes will not be saved between
sessions.
To assuage the wary and to avoid the necessity of disk partitioning, Ubuntu can be installed in a Windows system as a file which allows a choice of both systems at boot time. Moreover the Linux installation can be easily and quickly removed from the Windows system from the 'add remove panel' just as if it were a Windows program.