A:AnswerOverclocked cpu. Went from GHz to 2.1GHZ. good bump in speed on the cpu. GPU is a gimped AMD 480. For a console priced at $400, its a real good Graphics chip. IT will keep this console relevant for some time longer. A no brainier purchase in my opinion.
A:AnswerThe PS4 Pro plays everything the original PS4 plays, disc or digital. The Pro gives you 4K and HDR support if your TV supports either or both.
To play multiplayer you need a PS Plus membership and the Internet on both machines.
As for only playing PS4 games... yes and no. You can't put any disc or download games from an older PlayStation into any PS4. But there are older games that have been reworked to play on it. There are several PS2 and PS3 games available for digital download on the PlayStation store that have been modified to work on the PS4. But that's the only way (on the store it has to say it works on the PS4). Putting in an older system disc is not possible, even with PS1 games (this is the first newer system that won't play them).
A:AnswerThey are 2 seperate features.
If you play 4k games a few feet from the screen, you'll get the benefit of 4k, but beyond that the human eye can't differentiate.
HDR will benefit regardless of distance, as it adds more gradient to colors, and brighter lighting highlights (think sunlight coming through a window into a dark room). How much you benefit will also be dependent on the brightness level of the screen, and of course both the game and the screen have to support HDR. A 10-bit screen (req for HDR 10 std; Dolby Vision req. 12 bit) can have more detail in the bright areas of the image, and/or more details in the dark parts of the image. It can also have a greater range between the brightest and darkest parts of the image, reducing the "banding" you can see when the image goes from dark to light. This is because standard 8 bit TV will display a bit over 16 million colors and the human eye is capable of seeing much more. A 10 bit display by comparison can display over a billion different shades of color.
