Breathing takes oxygen in and carbon dioxide out of the body. Aerobic organisms require oxygen to create energy via respiration, in the form of the metabolism of energy-rich molecules such as glucose. The medical term for normal relaxed breathing is eupnea.
A man breathing:
So which part do you like better?
Breathing in or Breathing out?
I love breathing in. Especially during yawning.
A man breathing:

So which part do you like better?
Breathing in or Breathing out?
I love breathing in. Especially during yawning.