One such issue is the size of the display. And while display size sounds like a simple enough topic---it’s whatever size in inches, measured on the diagonal---it’s gotten complex in recent years thanks to the evolving nature of the smartphone.
Today, smartphone displays aren’t just “bigger” than they used to be---again, as measured in inches diagonally---they’re also taller, top to bottom, and they are different widths, side-to-side, leading in sum to different aspect ratios. Taller and wider displays let you see more content, or at least provide a bigger canvas for that content, but they can also lead to heavier handsets that are hard or impossible to hold and use with a single hand.