Pranayam is a word derived from Sanskrit where “prana” means life force and “yama” means control. Pranayama yoga, also known as breathing yoga, is founded on the beliefs of controlling ones’ breath and is almost always a part of yoga. Pranayama play a central part where along with asanas/postures, it helps you to get in tune with your bodies.
Breathing is the very essence of life and the first thing we do when we enter this world and the last thing when we depart. In between, our bodies absorb roughly half a billion breaths.
The benefits of a regulated practice of simple, deep yogic breathing include:

Muscle Relaxation

Increase in energy levels

Reduced anxiety, depression and stress.Lower/stabilized blood pressure
Nadi Shodhana or Alternate Nostril Breathing

A yogic practice that immediately helps you to feel calmer whenever you are feeling anxious or agitated.
Brahmari or the humming breath:
The inhalation is similar to the ujjayi (detailed above) and during exhalation one has to hum like a bee. The humming results in a resonating vibration in the head and heart. Proceed to take ten deep breaths in this manner and then another ten deep
Bhastrika or the bellows breath

A word of caution: This exercise must only be performed under supervision. Close the right nostril and inhale twenty rapid bellows-like breaths through the left nostril. Repeat with twenty more bellows breaths through the right nostril while keeping the left nostril closed.