Better graphics, bigger world, better AI.

Better graphics and/or bigger worlds depending on genre. Also faster and better UI and better controller.

It's clear to me that the difference between this Ps4/xb1 and last gen is not nearly as perceptible as I hoped. I think nextgen with 4k will really make a huge difference. Add the obvious bigger worlds dynamic and Gen 2 of the VR headgear and it will hopefully be very significant.

The dictionary definition is:

pertaining to the next generation in a family; also, pertaining to the next stage of development or version of a product, service, or technology

So anything that is considered a successor basically. But what it's been used to describe the past few years is pretty much whatever you want it to mean.

Slightly better graphics. That's it.

uncharted or infamous or saints row

To be completely honest the graphics are the main thing that I notice and appreciate. 6th gen was when 3D gameplay basically became unlimited, AI has been as stupid as it's been since the beginning of time, hardware features have hurt just as much as they've helped... Yeah, pretty much just the graphics.

Nothing. There is no real expansion above the prior. It's all just just smoke and mirrors. HYPE!

As said by the console makers and devs that want your money...

More or less. Couple changes here and there, but when the story adventure games left off, the fps picked up...