- When the Android-powered device is in host mode, it acts as the USB host and powers the bus. When the Android-powered device is in USB accessory mode, the connected USB hardware (an Android USB accessory in this case) acts as the host and powers the bus.
- We need the android powered device to be in USB host mode since the USB device we're connecting to the phone is a webcamera
android.hardware.usbpackage provides support to communicate with USB hardware peripherals that are connected to Android-powered devices