What's the difference between Ubuntu 12.04 LTS for free and the Official CD of Ubuntu for $5? I didn't know the difference.
There's no difference. The CD is just an annual thing they do for people with slow connections and to raise funds for Ubuntu.
They charge the cost for the CD/DVD, maybe shipping & handling and the seconds it takes to burn it. This helps in several key points:
For the 12.04 for example you would get a box cover like this:
And the CD Cover like this:
In the case of Ubuntu, they charge 5$ for a pack of 5CDs + S&H. Is it worth it, most definitely yeah!. I mean you are getting all that for a little more than 5$.
The only downside is that you'll turn into my dad. He has a collection of all Ubuntu / Xubuntu / Lubuntu / Kubuntu / Edubuntu... CDs since it came out. And I MEAN a collection that he doesn't even take out of the cover box. I mean do you know how many versions of Ubuntu there are and types of flavors. It almost looks like a music collection if you look at it from the side.
There is no difference. Both are the same. But if you like to have the official CD, for keepsake, you can do so. Plus if you have a slow connection, or planning bulk deployment, getting the CD would be an idea.
To buy Ubuntu CD:
Download Link for Ubuntu CD: