In my opinion, it mainly stands for low-risk productions where you recycle a proven core game mechanic with amazing and new graphics. For example, the Assassin's Creed series where each game looks unique and great, but they all play very similar.
That’s a little backwards, AAA games are expensive which makes them inherently risky. This is why most successful companies try to minimize risks by using proven franchises and gameplay.
However, you do see plenty of exceptions like the original Dark Souls which took serious risks. Which was then followed by two lower risk sequels.
