Commonly the terms respiration and breathing are used as if they have the same meaning but actually the two are very different processes and they need to be distinguished from one another. In simple terms the respiration is a large scale process of the living body and breathing is just a phase of the overall large scale process of respiration. Breathing is the starting phase of the process of respiration and respiration is a process which has its roots at the cellular level of the bodies of living organisms. To elaborate the difference between respiration and breathing, they need to be separately defined and understood.
Respiration:Respiration is one of the characteristic processes of life and without the process of respiration life cannot survive. It is one of the key features of life. The process of respiration can be defined as the process in which the organic food is utilized at cellular level to produce energy for all the activities of the body. From the definition it is clear that respiration is the process which is responsible for production of energy for the activities of living organisms. Without respiration the energy demand of the living bodies cannot be met. Because energy is continuously needed by the living organisms therefore respiration is also a continuous process and it continues 24 hours a day. In the process of respiration oxygen is used to oxidize the organic food materials to obtain energy from them thus oxygen is a necessary requirement of the process of respiration and without oxygen respiration cannot take place. The actual process of obtaining energy from food occurs at the cellular level but the transport of oxygen to the cells and obtaining of oxygen occurs at a bigger level.
Breathing:Respiration needs oxygen to burn the food to get energy from it and breathing is the phase of respiration in which oxygen is brought into the body. Respiration is a chemical process but breathing is a purely mechanical process in which the lungs suck the air in and then expel it out. When the air is sucked in, the oxygen is transferred from the lungs to the blood from where it goes to the cells of the body. When the air is expelled out, the carbon dioxide is excreted from the body. So it is clear that breathing is that phase of the process of respiration in which the body gets oxygen from air and releases carbon dioxide out.