‘Yog’ in scriptures has two connotations: 1. Philosophy of Adwaitvaad, which states that every soul is integral to supreme soul of God. All souls are are part of one big continuum  in metaphysical state, called Purusha.  A segment of it, deluded, in bodied, is known as souls which is subject to re-births Depending on Karma and soul’s self-elevation, rebirths take place. Purusha, the Grand continuum of consciousness, represents itself alongside souls and alarms beings, as they do wrong. Like we can see ourselves in a mirror, souls can see it’s true self in purusha, but they cannot see themselves if veiled by Triguna nature. If you can recognise rajas and tamas elements in triguna that cause delusions and elevate to Satwa, you can see Purusha within. Purusha within, which is the element of God commands his directives subconsciously, but souls fail to follow. Note that souls and Purusha are distinct, until they unite. In Kapil Muni’s explanation as well as in Srimad Bhagwad Gita, souls can be enemies or friends depending on if they see Purusha and recognize it. This recognition is also the union of the soul with Purusha. This is called Yog. This is when egalitarian and utilitarian outlook is developed in one’s thoughts and action.
2. Yog also stands for ‘adjoining’ to certain procedures and ways. This is seen in Soul’s categorical process of behaving and performing actions – that is joining beliefs (Bhakti-yog), trusting more in actions followed by action learning (Karma-yog), inclined to knowledge and its application in behaviours (Gyan-yog), enquiring in-depth, research and inventing new knowledge (Dhyan-yog). The first two are primarily belief based while latter two are ‘Sankhya’ or logical techniques.
Both the connotations have a practical application. While realizing oneself with unified cosmic soul of the Brahm instills oneness with all living beings, thus, leads one to be egalitarian, utilitarian outlooks and develop high empathy for all. This is attitudinal change of character itself where selfishness dissolves with empathy. The other connotation of yog helps people to adopt special process of thinking and acting, which is quite innate to one’s character, and is the true Dahrma of people, as stated in shloke 17-2, discussed in section 3 of this Appendix.
Such concepts may be logically accepted if not realized and that is Sankhyayog. In either way, one exercises collectivism in thoughts and actions. It has socio-psychological advantages for everyone. At higher plains of consciousness one thinks as a society rather than as an individual, and  the future course seems to be visible. Forgiving the mistakes as well as killing the dangerous to save innocent, becomes justified, contextually. Ethics and behaviours people adopt matters and this makes societies constructive or destructive in the long run. Ideologies that promote and preserve sustainable humanity become supreme. Trifles of daily life look to be a sham and the happiness comes from holistic spiritualism-led-materialism.

Stay in Yog, (in realization of spirituality), perform your duties and actions, detached, O’ Arjun. Whether successful or not, they are the same, such spiritual science is said to be Yog.
In Yog, every action is validated from spirituality and is an accomplishment in trying itself, irrespective of the material outcome. Raising one’s consciousness, especially in view of delusions around and aligning with nature holistically, Yogis perform duties for the welfare of humanity. In Yog, spiritual success is guaranteed; material success is in the eyes of beholders. Some see an Olympic medallist, a rich businessman, a celebrity or a leader winning election as success, yet some find satisfaction in doing good things around. Success in accomplishment ensues much more happiness than the recognition. An innovator develops a technology knowing very well the importance of the outcome, yet, unable to find right evaluators and investors. It is not his fault, he has done his job and is happy about it. It is the fault of the society which fails to recognize his achievements and promote it. Such societies are unable to utilize human talents and potential, and miss an important part of development, which makes them dependant on imported technolgoies and goods. Definitions of success are different for people. Material success depends not only on oneself but others as well, while spiritual success is solely on the soul. While former creates further wants and desires, the later  renders lasting bliss. This shloke indicates that for spiritualist Yogi-in-action, material success or not are all the same.
History of the world is full of examples of great souls who dedicated their life for people yet they were ignored and revered much later. They never cared for success or recognition – they just did what was needed. They maintained equipoise before and after the Actions, with or without the success. Such dispositions are possible only with Yog. In that state one’s consciousness expands engulfing others and selfishness dissolves with empathy and behaviours change to giving, rather than receiving.
How to get in Yog?
Yog sets the direction for one’s life and helps one’s day-to-day learning and decision-making. There are four streams of Yog: Bhakti Yog (by belief), Karma Yog (by actions in belief), Sankhya Yog (by logic) and Dhyan Yog (by elevated consciousness). The four of them can be categorized in two segments, differentiated by blind faith or logic-led-faiths. Bhaktiyog and Karmayog are paths mainly based on belief. One believes as preached and acts accordingly without asking questions. Other two are paths of reasoning and knowledge. Believing is the first stepladder. Other stages of yog come in sequence. Not only relgions, but scientific studies also follow the same paths. What is taught to us in schools we believe in that, later we experiment and research more during higher studies. However, believing can also be misleading and dangerous as people may be indoctrinated wrongly. This too happens in sciences, as wrong hypothesis prevails for a long period of time, unable to explain certain events, until new philosophies replace old ones. Lot of drugs used for long are later declared fatal and banned. We call it current stage of sciences, thus, the human knowledge steers ahead, creating knowledge from the darkness of ignroances. Just the same way other wings of humanities develop including religions, and also every single human life evolves through knowledge and experiences gained in life. However, religions when not understood logically, fail to develop further, instead, they are misunderstood by myopics as Mumbo-Jumbo. Their ignorance about religions must be respected, as it is never taught logically in any organized institution, despite having tremendaous impact in everyone’s life directly or indirectly. In purified Bhaktiyog, people are advised to  help others with warmth and build a loving and stress-free society. Sankhya is logical reasoning, the same as scientific analysis. It’s  heightened form coupled with meditation based mind power enhancement, is Dhyan Yog. With enhanced mind power, even the difficult logics are understood fast and the process appears to be direct realization.