Linux Live CDs allow you to test Linux without having to install it. Just burn a distribution to a CD and you can run Linux off this disk. Live CDs (also called bootable CDs) are easy to use and they don't harm your computer.
Introduction to Live CDs
So many Linux distributions, so little time and hard drive space. What can you do if you only have one computer and want to test out an interesting looking version of Linux?
Normally, you'd let it to take over your hard drive. Or, you could partition your hard drive so Linux shares it with another operating system. But if you find that a particular Linux distribution isn't quite right for you, getting rid of it or changing it can be a chore.
Another alternative is to use a Live CD. A Live CD is an operating system that boots from a CD -- there is no need to install the operating system on a hard drive. A Live CD is a great way to test out Linux without worrying about what it may do to your computer.
Getting a Bootable Linux CD
The best way to start with a bootable Linux CD is to burn your own. All you have to do is download an ISO image from the Web site of whatever distribution you plan to use (you can find a list here). An ISO image is a snapshot of the contents of a disk that's wrapped into a single file with the extension .iso -- for example, KNOPPIX_V6.4.3DVD-2010-12-20-E.iso. The ISO image contains the core operating system, the software that's bundled with it, as well as the necessary boot and disk information.
Burning an ISO image to CD is easy, but the process differs slightly from burning your ordinary files to a CD. How to do it will depend on your operating system and the burning software that you use. For example, if you're running Linux then you can use software like K3b or Brasero. On Windows, try ISO Recorder.
Running Linux from the USB/CD
Once you have the ISO image burned to a CD, just pop that CD in your CD-ROM drive and restart your computer. When your computer starts, it should boot from the CD.
On start up, the Linux distribution will try to detect your hardware -- everything from the video and sound cards, the network card, and even wireless. How well or badly a Live CD does this depends on the Linux distribution and the age of your hardware. Usually, it will detect everything. Wireless can be tricky, if only because some Linux Live CDs don't include wireless drivers.
From there, you can fiddle around with Linux to your heart's content. You can use the bundled software, work at the command line, and change the look and feel of the user interface. But remember that the Live CD version of a Linux distribution will start and run slower than one installed on a hard drive. That's because the software is loaded into memory and anything else is read off the CD which takes time. But you get a good idea of what Linux is like and what it can do.
The best thing about using a Live CD is that you can test as many different Linux distributions as you like. This gives you a chance to find one that fits your bill. It's easy, and all you need to do is download some ISO files and burn a few CDs.