Why Linux instead of Windows?
The choice all boils down to two things: security and stability. There is a good chance you have already experienced the basic instability of a Windows system. If you're setting up any kind of professional server, you can't afford to have down time.
Over the past ten years, Linux has proven itself as a server operating system. Most Linux workstations are only rebooted for kernel upgrades or hardware installations. I've seen Linux servers that haven't been rebooted in over a year. When was the last time you could say that about Windows?
Linux is far more secure and stable than Windows and its derivatives. Historically, there have been far less vulnerabilities in Linux than in Windows. The vulnerabilities that existed in Linux have been patched or resolved within a day or two of their discovery.
As a bonus, there are virtually no Linux viruses. Most virus writers have a "don't crap in your own back yard" policy towards Linux - since many virus writers develop in a Linux environment, they're reluctant to develop viruses for it. Even if they did, the user-based model behind Linux would contain the virus' damage to the files owned by the user - it should never, under normal circumstances, affect the system files.
If something does go wrong, there's a huge support base available online. Whether it's the included documentation, newsgroups, websites such as http://www.linux.com
or commercial support through companies like RedHat support for your problem is readily available. At the end of this article you will find a few websites that should be helpful if you get in a bind
Linux can be found in places as varied as Internet servers or manufacturing systems. With its low ownership cost and huge support base, it's easy to see Linux remains a popular choice in the server market.
How is Linux different from Windows?
File management is an initial roadblocks for new Linux users. In Windows, files are contained in directories, which are located on different drives. Under Linux, there is no such thing as drive lettering. Rather than C:\, you refer to your base (root) directory as /. In addition, directories are denoted with a forward slash (/) rather than a backslash (\).
There are 4 directories in the root of your Linux system you will become very familiar with.
/etc contains most of your application and system configuration files. When a new application is installed on the system it will usually place its configuration files here. If you're looking for a configuration file, it can most likely be found here.
/usr is the Linux equivalent of C:\Program Files. Whenever you install an application, its binary files will be placed here.
/var contains "variable" information - things like databases and web documents.
/home contains user files. This, for example, could include backed-up data from their workstations, or HTML documents for different users on your network.
These directories can exist on the same hard drive partition, or can be put onto separate hard drive partitions - Linux will see them as the same file system, regardless of where they are physically located.
Another important difference between Windows and Linux is the role of user accounts. User accounts exist in Windows, but offer no system security whatsoever. Under a Linux system, a user is segregated from system functions, and even other users. Users can also be placed in groups, such as www-data, to allow them to maintain certain system functions a regular user wouldn't be allowed access to.
The final, and largest, difference is that Linux is maintained chiefly through the console (text-based), rather than through a GUI interface. Linux itself is a text-based operating system. Workstation setups often include X-Windows alongside KDE or a similar window manager to make things more usable, but the majority of your system's configuration will be done in a text-based system.
Since we're running our Linux system as a web server, we won't be installing X-Windows.
credits: Darren James Harkness - http://www.staticred.net