For the term meditation, we can say that it is the advanced level of Samadhi and yoga. Though the basic purpose behind meditation is also to avail better health and a peaceful and tranquil life the method is a bit complex.
Yoga is a basic step towards the process of getting connected to your spiritual powers. It consists of a simple to complex postures which are to be followed in a particular sequence. With the passage of time, a yoga trainer gets success in controlling his breath and getting access to spiritualism.
Pranayama yoga, a technique that is practiced just to train yogis to control their breathing system and regulates it in the right directions. Pranayama yogis are trained for prolonging and controlling breathing systematically.