The vagus nerve is one of 12 cranial nerves and is the only one that "wanders" throughout your entire body - connecting to and affecting almost every organ system of the body. It is also the nerve bundle that helps us moderate the balance between fight/flight/freeze and rest/digest/socialize in our autonomic nervous system. By toning the vagus nerve, we can improve the downshifting of our nervous system and help boost digestion, balance energy, care for our heart, support our liver, and boost immunity. And we can affect the vagus nerve through simple things such as breath.
In this practice we work with the 3 part diaphragmatic breath and the "Voo" exhale/hum taught by Dr. Peter Levine. For more information on what the vagus nerve can do - checkout Dr. Stephen Porges and Dr. Peter Levine (both have a lot of interviews, practices, and informative books).