UWP apps can automatically adjust the size of controls and fonts based on the resolution of the device where it is running. When the app runs, the system executes an algorithm to normalize the display of each control running on the screen. For example, a control having a 20 pixel font size should look proportionate on phones, tablets, desktop PCs, laptops, and/or Surface Hubs:

When you design your app, you need to make sure that effective scaling has been maintained for all the device families that you are going to target running the app.