PC Magazine offers excellent comparison of current 4K verses evolving 8K resolution standards.

https://www.pcmag.com/news/what-is-8k-should-you-buy-a-new-tv-or-wait

8K is a higher resolution than 4K—and that’s it. 1080p screens have a resolution of 1,920 by 1,080 pixels. 4K screens double those numbers to 3,840 by 2,160 and quadruple the number of pixels. 8K doubles the numbers again, to a resolution of 7,680 by 4,320. That’s four times the number of pixels as 4K, which means it’s 16 times that of a 1080p TV.

For context, look really closely at your TV. Try to find a single pixel (not the individual red, green, and blue lights; those are subpixels, which means you’re too close). If you’re looking at a 4K screen, imagine four pixels taking up the space of that single pixel. If you’re looking at a 1080p screen, picture a grid of sixteen pixels, four by four, within that single pixel. That’s 8K. It’s much sharper than 4K and much, much sharper than 1080p.

Most people can expect to wait at least two years before 8K TVs are a realistic choice. In 2020 and 2021, we’ll probably start to see 8Ks become the new “premium” TV tier, still a solid jump in price but presented as the top-of-the-line consumer models instead of cutting-edge technology you have to special-order. Expect to see midrange 8K TVs, likely in the $1,000-to-$2,000 range, by around 2022. The technology will have been polished and optimized to make manufacturing 8K TVs at a large scale to be sold at those prices by then.