From Yoga Sutras, Yoga firstly starts from mindset control until the mindset follow special rules to adjust and improve gradually. In the end, obtain self-consciousness and liberation. It is a process that accumulated by periodical purposes to reach general objective. It is a process that does not accomplish in a short time, which includes various objective with different layers. Which means, there is a general objective for the transform of mindset, and also includes all sorts of steps to finish, which forms a complete level. That is the practice process of yoga.
Generally speaking, the objective of yoga can be summarized by Yoga Sutras, as keep the true nature, or interpreted as returning the original features to perceiver. This definition is like the Chinese Zen school of Buddhism, original features, local surroundings, Buddha-like. This the most fundamental and highest objective. In general, yogi focus mainly on the transform and control of mindset. Or more specifically on the periodical objective, like position or meditation, and ignore the general objective.
For all the process of yoga, Maitrayaniya Upanishad has classified that into six branches: for concordance, which refers to six branches, breath, knowledge, peace, contemplation, reservation, sitting quietly and meditation. In the perspective of Upanishads, there are eight explanations: abstention, reflection, practice, breath, restraint, insisting, perseverance, Samadhi.
From Yoga Sutras, it combines with ancient theory and produces eight branches, which becomes the yoga theory popular among people.
The first one is abstention, including no violence, no lying, no stealing, no fleshliness, and no greed. The five rules are basically the same as the five rules of Buddhism. (no killing, no lying, no stealing, no carnality, and no greed). It sounds like religion forbiddeness. As a matter of fact, these are all the needs for self-cultivation and the needs for purifying souls and constraining body and mind. Hence, for a real yogi, all these rules are necessity. As emphasized on Yoga Sutras, all these rules are the basic standard for one’s behavior, it should should be restrained by time, location, purpose or level.
The second one is reflection, including inner or outer cleaning, contentment, ascetic practices, reading classics, praying for universe. All these are the progress and basic of yoga practice. Comparing to abstention above mentioned, that uses external materials to purify the mind, but reflection is self-regulation.
The third one is adjustment, which mainly refers to sitting. Of course it will not exclude movements that settle body down, for example, yoga position. Overall, as listed on Yoga Sutras, the position must be comfy and cosy so that it controls worries and meditate on infinite. The lotus pose is the common meditation position.
The fourth one is breath adjustment. Yoga Sutras says breath adjustment is the control of breath in and breath out. Through breath adjustment, one will find the inner power and brightness, so that it obtains the power of focus. From which shows that breath adjustment is the preparation for meditation.
The fifth one is mind control, which refers to the control of spirit, consciousness, and emotion. If the heart separates from body, the sense will separate from its body. Finally, reaches the control of overall sense.
The six one is focus. Focus refers to the centralization of consciousness on something and some specific one. focus aims to concentrate on something.
The seventh one is meditation. On Yoga Sutras meditation is stream of consciousness flowing constantly into the objective, which means thought regards the focused objective as target and constantly and dedicatedly to sense it. The difference between focus and meditation is that focus is the process to concentrate on something. Whilst, meditation is connecting the heart to something tightly.
The eighth one is Samadhi. On Yoga Sutras, Samadhi refers to the radiating of inner nature, and will not be changed and affected by the receiver. It can also be coded as only the existence of mediation that the self-consciousness disappeared. Which means the self-consciousness disappeared that the it only focus on the receiver that reaches the state of union of mind and body.
These eight rules are all concerned with meditation, only in different level, layer and depth. In contemporary times, besides yoga poses, people all refers yoga as meditation. Meditation and poses constitute yoga theory, which meets the connotation of Yoga Sutras.
At this point, we almost grasp the basic meanings of yoga, which includes above mentioned eight rules. For which we can classify into five categories: morality, adjustment, breath, mindset, meditation.
As a yogi, I have been practice yoga for almost five years. Every time when I practice yoga, I always put on yoga clothes for a professional practice and get the desired result.