This terminology is meaningless gibberish and the product of youtube essayist wank regardless of it's original origins in which no one had used it during that time anyway. It's presently a smoke screen for amateur indie developers to hock their second rate trash onto the market/unsuspecting consumers and probably even some of the tactics of professional developers to make you think you're playing something that you might want to play like Deus Ex or Thief. But nothing that calls itself those words will ever be interesting to play like either of those two games were.
