What is a live CD?

A non-dead cd.
Ok, it is a cd with a linux distro on it. One that does not need to be installed. You can run linux from the cd.

A live cd is a linux distro that boots from and runs completely from a cd. There is no need to install anything with a live cd and nothing is written to your hard drive although you can usually access the hard drive from most live cds. There are numerous linux live cds but the granddaddy of them all is knoppix. Here's a link that attempts to catalog the current ones available:

http://www.frozentech.com/content/livecd.php

Many, if not most, live cds can also be installed to your hard drive if you see what you like when running directly off the cd. System performance will be slower when running off a cd as opposed to a hard drive linux install. However, live cds are a good way for someone new to linux to get a feel for what linux is all about without having to go through a hard drive install.

A couple of other points if you're new to this:

Make sure if you're burning the live CD ISO that you make a bootable ISO or else it won't work

Make sure your BIOS is set to boot from CD

Wonderful-thank you all for the info and tips!

Gosh ... The liveCD concept is great! I recently downloaded Knoppix, and found that it has all sorts of capabilities, all right on the CD! What does this mean? Basically I've got a mobile system on CD. Plop it into just about any CPU, and run my desktop apps, Internet, mail, etc. Also use it as a tool for data recovery or whatever! Though I haven't tried it yet, I'm thinking a combo LiveCD and memory stick would work great together.

The use of a LiveCD and a usb stick works great. SOme distros can be installed on a usb. The way I like to do it is use the livecd normally and save my setting/home on the usb.

I had to do that for a couple months when my harddrive died, PCLinuxOS saved me from going crazy.

@SlowCoder: Yep! Knoppix saved my bacon when my hard-drive went to Valhalla. Plus I had it installed for about 3 months for evaluation. It's a top distro; that LiveCD should be any Linux users tool box.

Okay-I'd heard the term but didn't know what it was. In fact, I think Ubuntu is live also but I didn't what to do with that. (I do have it installed.) But for when I work offsite, it sure would be great to take the CD with me and just use it and then save the information on the USB stick. And as you say, you never know when a hard drive might go bad. It sounds like you all are pretty happy with Knoppix; I'd like to look into that. It's nice to know you can install some distros from the usb also.