Both the iPhone X and the Galaxy S8 Plus have larger displays than the typical smartphone release of recent years. But there's still a gulf between the two in terms of size—the iPhone X screen measures 5.8 inches, while the Galaxy S8 Plus measures 6.2 inches. Both smartphones feature OLED technology (the display on the iPhone X is actually made by Samsung) and very high resolution. The S8 Plus resolution comes in at 2,960 x 1,440, while the iPhone X is a bit shorter on pixels at 2,436 x 1,125.
A defining feature of both phones is that the bezel around the display is minimal. Importantly, though, the iPhone X does have a notch cut out at the top of the screen for a camera system and other sensors. So, in terms of having an edge-to-edge design, the Galaxy S8 Plus is closer to the mark.