"High resolution" could mean any display >= 1080p or so, whatever size (6 inches, or 6 feet). DPI, being "dots per inch" relates to resolution for a given phys

"High resolution" could mean any display >= 1080p or so, whatever size (6 inches, or 6 feet). DPI, being "dots per inch" relates to resolution for a given physical size, so a "low resolution" 720p display that was only 1 inch across would have a high DPI (in this case, 720 dots per inch), but a "high resolution" 4k display at 50 feet across would have a low DPI. Generally speaking, the higher the DPI the harder it is to discern individual pixels, and the better for viewing fine details.