How Do I Talk To 4th Graders About IT?
When it comes to kids, visualization is very important.
Try to connect to their day to day life. What do kids use computers for? Get them involved by asking what they use on a computer that is connected to the internet and ask them how they think it works.
You could be pleasantly surprised by how much imagination they have. Intrigue them. The history of the internet might prove to be more interesting than how sendmail works or how to configure a kernel.
Explain them about the problems the internet is facing because we run out of IP addresses (you can use China as an example).
Talk to them about they stuff that matters to them. At one point or another, everyone gets introduced to an IP address.
How does the internet translate URLs to IP addresses when they visit their favorite website.
Oh, and bring Tux along. Kids like penguins better than butterflies in unnatural colours.
Don't ask them why VI is better than Emacs though. They might start to get physical as of a lack of arguments to defend Emacs.