Ha-tha (sun-moon) yoga is the process of "bringing together" or joining.
It Guides one to experience the limitations and expansiveness of the body, spirit and soul.
Its goal is to bring the physical body into a solid state of health so the soul has a fitting vehicle of expression to work through.
It embraces many practices, including physical postures and breathing excercises (pranayama) which also act upon the physical nervious system and etheric body - bringing the vital energies of the physical and etheric bodies under conscious control.
Hatha Yoga Practice takes the form of Asanas (postures), Pranayama (control of breath), Relaxation, Mudras, Bandhas etc. each part
By long term practice one is able to gain control of the physical body and the subtle life force called Prana.
When body, spirit and soul are "At Home" then meditation comes naturally.