One UI is the marketing name from Samsung for a refactored user interface on Samsungs own Android devices, which was installed together with Android9.0 on supported devices. One UI was implemented the first time in Samsungs own interface Samsung Experience in version 10.0.
At the 14th of october 2019, Samsung started the beta phase of their second iteration of the One UI interface on the Samsung Galaxy S10 and Galaxy S10+.Cite error: The opening
<ref> tag is malformed or has a bad name One UI 2 is based on the recent Android-Version Android 10. The interface itself was mostly kept the same, only minor things were changed, which are supposed to result in a better overview.
The refactored user interface is especially made for using a smartphone with one hand only because of a otherwise big touchscreen. A big screen is making the usage with onehand only more complicated, as some elements to control the features of the phone are place at the top of the screen. With One UI, the screen is logically divided into a View and an Interaction area, whereas the top one should be used to show information to the user only, whereas the elements to control it should go to the bottom area. However, the implementation of this is not automatically applied globally to all installed apps and screens, each app and program needs to adjust their menues themself, as it is done in Samsungs own apps and system-screens (through Samsung Experience).
With One UI Samsung implemented the possibility to turn on a so called night mode. Apps, which support such a mode, are then using a theme with a higher contrast and a dark/black base color.