5K resolution
5K resolution talks about a horizontal display resolution of about 5,000 pixels. In monitors and consumer media, 5120x2880 is a common 5K standard. The 5K used for iMac's display is 5120 x 2880 px.
5K Resolution Media
Comparison of common display resolutions
Samsung 105 inch Ultra HD television
Intel-CPU based iMac with a 27 inch 16:9 aspect ratio screen, released by Apple in October 2009. (Intel based iMac models released prior to October 2009 used screens with a 16:10 aspect ratio. PowerPC-based iMacs released 19