doesn't have a in its display; instead, it has a cutout for the front-facing camera. The cutout for the camera, sometimes referred to as a hole-punch, is either a circle or a pill-like shape depending on the S10 model you have.
The cutout is in the top-right corner of the display, and for some, it's downright distracting. Thankfully, Samsung included an option to hide the hole-punch camera with a quick settings change.
If you're among those who can't deal with the hole-punch cutout, open the Settings app on the Galaxy S10 and go to Display > Full screen apps and slide the switch next to Hide front camera to the On position.
The interface on your S10 will flash and rearrange itself as it makes the top section of the display black, essentially hiding the cutout. You'll also gain more space for your phone to display app notifications and other information in the status bar.