Asanas may be classified as (1) Meditative (2) Cultural, and (3) Relaxative:-

1. Meditative Asanas are sitting postures, which maintain the body in a steady and comfortable condition. By various arrangements of the legs and hands different Meditative Asanas are performed. The characteristic feature of the Meditative Asana is, however, keeping the head, neck and trunk erect.

2. Cultural Asanas involve static stretching which brings about proper tone of muscles. They contribute to the flexibility of the spine and render the back and spinal muscles stronger. They also stimulate proper working of the vital organs in the thoracic and abdominal cavities. There are innumerable varieties of Cultural Asanas, which are performed in sitting, lying and standing position.

3. Relaxative Asanas are few in numbers. They are performed in the lying position and are meant for giving rest to the body and mind.

Pranayama
These practices bring control over the respiratory impulses, which form one of the channels of the flow of autonomic nerve impulses. Holding of the breath for a prolonged and comfortable time is an essential technique of Pranayama. However, in the initial practice the breath holding phase is completely avoided and emphasis is put on the controlled inspiration and expiration with a time ratio of 1:2 between them. The expiratory phase is so controlled that the following inspiratory phase is not effected in its slow and controlled inspiration. The main purpose of Pranayama is to gain control over the autonomic nervous system and through its influence the mental function is also controlled and regulated. It is useful in higher Yogic practises like meditation.

Bandhas and Mudras
These are locks and holds of the semi voluntary and involuntary muscles in the body. They decongest the vital organs, improve circulation and nutrition by pressure manipulations and contribute to general health and emotional stability. A difference is made between the Bandhas and Mudras on the bases of their use in Pranayama. Mudras that are used in Pranayama are usually called Bandhas because they bind and channelise a particular nervous activity in a particular place or direction. Jalandhara, Uddiyana and Moola are important Bandhas. Some Asanas are called Mudras because of their specific effects and channels through which the effects are brought about.

Kriyas
These are purificatory processes usually classified into six division and therefore they are often called Shatkriyas. These are Dhauti, Basti, Neti, Trataka, Nauli and Kapalbhati, each one of which consists of many subsections. They increase the range of adaptability of the tissues forming various organs and systems and raise the threshold of their reactivity. Kriyas are air, water, friction and manipulating movement. The regions of cleaning involved in various Kriyas are Naso-pharyngeal, Otocranial, Gestro-oesophageal, ano-rectal and intestinal.

Meditation
This is the practise involving control of the mental functions, which start from the initial withdrawal of the senses from external objects to the complete oblivion of the external environment. There are several techniques of meditation. It is a process of absorption in which the individual tries to turn his attention to dwell upon a single object, sound, concept or experience. It is not always safer to start one’s practice in meditation without preparing adequately through Asanas and Pranayama. The basic principle of Meditation is to develop internal awareness.