Agreed. I don't think the language is right for newbies:

"What is computing with Unix?

Unix is a family of operating systems and environments that exploits the power of linguistic abstraction and composition to orchestrate tasks."

That isn't a question a newbie would ask or an answer they'd understand. Instead, I think the following would have been (less accurate but) much more helpful:

"What is Unix?

Unix is just an operating system, like Microsoft Windows or Mac OS."

Know your audience!