The Xbox One has three power states: off, on and standby. The first two are self-explanatory while the standby mode will ensure that the system boots faster using voice or controller input.
It is so fast that even your TV will have problems in keeping up with the Xbox One. We expect most people to keep their console in a standby state.
Standby is the mode Microsoft wants people to be in with their consoles so that you can get back to gaming or watching TV really quick.