There are multiple components running through your neck that coincide with the spinal column. Nerves, blood vessels, the larynx, muscles, all kinds of things. Traumatic injury to the neck can break one or many of those things and not all in the same way, even with similarly natured injuries.
Someone could break the bones in their neck while maintaining an intact nervous system and not lose the ability to move around, or someone else can snap their nerves or puncture their larynx and suffocate. It all depends.