Dell S2721QSA User Manual page 57

Others Select this option to adjust the OSD settings, such as
DDC/CI, LCD Conditioning, and so on.
Display Info Displays the monitor's current settings.
DDC/CI DDC/CI (Display Data Channel/Command Interface)
allows your monitor parameters (brightness, color
balance, and etc.) to be adjustable via the software
on your computer. You can disable this feature by
selecting Off. Enable this feature for best user
experience and optimum performance of your
monitor.
│
Operating the monitor 57