Grove is a convenient plug-and-play system with specialized interface, but that doesn't mean it couldn't be used in open ecosystem like breadboard. With this special designed conversion cables, you can easily integrate the comprehensive Grove system with breadboard or other microcontrollers that don't have compatible Grove - Base Shield for now. If you are tinkering around Raspberry Pi, Cubieboard or Beagle Bone and be fond of the advantage of Grove, this conversion cable is recommended. And if you are tinkering around Arduino or Arduino Mega, Grove - Base Shield can be a more direct and convenient tool.
More information about how to choose a cable, please refer to this manual.