A couple of friends and family have been asking:

• What’s up w/ the status updates I see quite often?
• What’s w/ the “@” (at symbol) next to names on your status?
• What the heck is a tweet?
• etc.

Rather than pointing them to Twitter’s site, I rather just show them this video:

[youtube]ddO9idmax0o[/youtube]

I hope that makes sense. Thanks to Common Craft. They have done a great job explaining it “in plain english” =)

Update
Some Twitter terms written by Peter Cashmore on Mashable.