In general, there are three types of hardware:
NB-IoT Chipset/Modem (baseband): NB-IoT protocol processing & frequency modulation.
NB-IoT Module: Contains the chipset/modem, Antenna Connection, UICC software support, external interfaces.
NB-IoT Device: ready to use including all relevant components for the respective use case e.g sensor, antenna, power supply, memory.
A device can also be a developer board, e.g. Arduino or Raspberry Pi.