A device is any machine or component that can perform an operation.
It is built upon logic gates and therefore only (accept|understand) a series of 0 and 1.
The first device was a transistor.
A device with its own set of instruction (ie machine language) is a programmable device. See Device - Programmable Device
The interface of a device is its pins.
The following interfaces are the only software interface:
Writing device drivers is essentially learning the functionality of each register and how to use them properly to control the device.
The 74HC00 is a chip device composed:
The chip comes with 4 gates that can be combined to create other logic gates (ie logic function)
On Windows
Example: Device by type view on the window Device manager: