Respiration involves 5 basic steps and the correct order of them is
Pulmonary ventilation ⇒ External respiration ⇒ Transport of gases ⇒ Internal respiration ⇒ Cellular respiration
Pulmonary ventilation is the movement of air, in and out of the lung passage, or put more simply, breathing.
External respiration is the exchange of gases between air and the blood in the alveoli.
Transport of gases is where oxygen and carbon dioxide are carried in the bloodstream associated with RBC (haemoglobin).
Internal respiration is the exchange of gases between the blood and body cells, oxygen out of blood and carbon dioxide into the blood.
Cellular respiration is the breakdown of molecules like glucose using oxygen, and the release of the carbon dioxide generated into the bloodstream.