The Galaxy S4 and HTC One both have HD displays with 1920 x 1080 resolutions. But there are some subtle differences between the two devices. First is the size of the display: the Galaxy S4 has a 5-inch screen while the HTC One has a 4.7-inch screen. Samsung's device has 441 pixels per inch (PPI), while HTC's phone, with smaller real estate, has a slightly higher PPI at 469.
Then there's the display type. The Galaxy S4, like previous Samsung phones, uses a Super AMOLED (Active-Matrix Organic Light-Emitting Diode) display technology, where as the HTC One uses IPS (In-Plane Switching) technology, as does Apple's iPhone. So what's the difference between these two acronyms? Not much, actually. Super AMOLED is an older display technology while IPS is newer and reportedly better for color contrast and less oversaturation. It's a close contest, and it may depend on preference -- for those who like bigger screens, the Galaxy S4 is the phone of choice. But for those who care more about cutting-edge technology, go with the HTC One.