OTA (Over The Air) is a special technology that allows you to update your phone “over the air”. To install a new version of the firmware or operating system, you don’t need to connect your smartphone to your computer, download the shell file manually, enter data into any program, or perform other actions. It is enough to connect to the Internet and go to the section with updates in the settings. And the update can be downloaded both via Wi-Fi and mobile Internet.
Not every device can be updated this way without talking about smartphones, Xiaomi. Completely outdated models with a version of Android 2, 3, and 4 had to update manually. All models of Xiaomi phones have been updated to Android 7, where OTA updates work fine. You can check for new firmware versions in the settings, specifically in the “My Device” section.