o) An enhancement to the Universal Serial Bus (USB) that enables portable devices to be cabled directly together (no computer required). OTG devices operate in "dual-role" mode and can be identified as either a host or a peripheral. When cabled to each other, an automatic negotiation makes one the host and the other a peripheral. Fully compliant as of USB 2.0, OTG devices began to ship in 2002.
Add a Mouse to a Tablet
A corded mouse is plugged into an OTG adapter, which plugs into the Micro USB port of this Android tablet.
Connect a Scanner to a Phone
Via OTG, this Walabot 3D scanner connects to the phone for power and the Walabot app. The scanner's Micro USB 3.0 jack also accepts the smaller 2.0 plugs as in this example (see Micro USB