What is 4K???

I mentioned 4K in my post about 1080P smart phones and this is to explain what 4K is. So essentially 4K or UHD depending in the branding is 4 times the pixels of 1080P, as for the 4K TVs themselves Sony is largely pushing the development while Samsung coming up a close second. The next hurdle is readily available 4K content Sony is the company that to my knowledge that has developed a system for deploying the content, I will include a picture of it. The main problem is cost for the Sony TV is $3309.00 I expect the price to drop below $1000 in about a decade. Now I will post a link for a explanation of 4K all credit goes to: cnet
http://reviews.cnet.com/8301-33199_7-57364224-221/what-is-4k-next-generation-resolution-explained/
P.S. I found another video explaining 4K, all credit goes to :NCIXcom
https://www.youtube.com/watch?v=V1qJGj-o7nU