It is not meant to be authoritative with regards to definitions or Yoga theory. Pranayama is a breathing practice in Yoga. It is particularly useful in situations where you feel threatened, because it helps you retain your calm. Pranayama is often recommended to the beginning occultist. Among authors who recommend it are Robert Anton Wilson and Aleister Crowley.
Preparation Wear loose-fitting clothes or no clothes at all.
Make sure your nose is clear, so you can breathe freely. If you have a cold, you will have to wait till you are recovered. Not only is it impossible to do pranayama when you cannot breathe through your nose but if you have a sore throat the first deep breath will send you into a violent cough attack. The purpose of the first step is to learn to distinguish between belly breathing and chest breathing. Lie on your back on a comfortable flat surface.