What does it mean when breathing is active or passive phase?

The processes of inspiration (breathing in) and expiration (breathing out) are vital for providing oxygen to tissues and removing carbon dioxide from the body. Inspiration occurs via active contraction of muscles – such as the diaphragm . This means Inspiration needs energy in the form of ATPwhereas expiration tends to be passive, unless it is forced.The lungs are passive during breathing, This means that they are not involved in creating the movement that helps inspiration and expiration. ... Contraction and relaxation of the diaphragm and intercostals muscles (found between the ribs) cause most of the pressure changes that result in inspiration and expiration.