On-the-go stands as OTG; this one is used to connect USB devices. It is one of the important things for a smartphone. This technology was first used in 2001.
Xiaomi Mi A2 Has USB OTG
Yes, It does. There is a USB OTG in this smartphone, through this feature, users can operate the USB supported devices such as USB flash drives, digital cameras, mice, and keyboards. To enable USB OTG go to the setting and find the USB option, if not enabled.