Screen resolution is just a measure of how many pixels appear on the screen, and how fast and how large items are displayed. Maximizing the Samsung Galaxy S21 Ultra with the highest resolution can provide you with the fastest images, but it may look smaller and will result in increased battery usage.
Moreover, you can reduce the resolution to make buttons and other objects larger but larger, and may appear slightly blurred. However, this will benefit your battery, so you may prefer to find a middle ground between expansion and battery life.
Besides, if you want the sharpest and smoothest display experience possible, you can get exactly that on the S21 Ultra. Alternatively, you can keep that smooth 120Hz setting and lower the resolution to Full HD+ for a more modest experience.
The following is how to manually select the screen resolution of S21 Ultra.
Step 1: Open the Settings app.
Step 2: Select the Display option.
Step 3: Scroll down and click on Screen Resolution.
Step 4: Adjust the slider to select the resolution you wish to use.
Step 5: Click the Apply button.
