It means when you are controlling the device for e.g. phone, computer, printer and etc.
It means the battery will operate a device for 8 hours before recharging is needed.
It depends entirely on the device. Give it a try.
Inflatable PFD
a device that is controlled by you touching the surface of it to operate
You use the touch screen to operate the iPad device.
The Network Interface cards
voltmeter
A motor will operate on 400 volts.
Every time that you turn on a light with a switch would be a situation where a series circuit could be used to operate an electrical device.
No. Bluetooth and infrared devices operate on separate frequencies.
Device drivers
An Android smartwatch wearer does need an Android device to fully utilize it. It will not operate on an iPhone.