'Nets' are basically the Internet as predicted/guessed by Orson Scott Card
> It is interesting to note that the World Wide Web, the modern form of the Internet, was not invented until 1990, 5 years after Ender's Game was published. Orson Scott Card accurately predicted how much influence the nets would have, years before they became a daily part of people's lives.
Source
> While there’s plenty of time for Internet discussions to turn around, I suppose, I can’t help but think that Card wasn’t terribly prescient with this prediction. In Ender’s Game, “the nets” are democratic and participative — anyone can join them, as long as they have the intellect to keep up — but there’s no problem with too much noise, trolls, spammers, and plain old stupidity.
Source
Some more disscussion can be found here