Yoga is the way of living. Gita is an art of living. Ultimate goal of both is to achieve the state of SAT CHIT ANAND. Yoga and Geeta both teach us to be in a state of equilibrium. In a balanced state of body, mind, thoughts, emotions and behaviour.

The meaning of yoga

The word Yoga is derived from a Sanskrit word called “yuj”, meaning “to join” or “to connect”. The question arises, what are we trying to join through yoga? Yoga is the process of joining, the mind and the body, the individual consciousness and the universal consciousness.
A yogi is one who understands the oneness in his body and nature, he also understands the oneness in him and the rest of the world. He understands the science behind it and knows the art of attaining this oneness.

Yoga, A science and an Art:

Yoga is a science as it comprises understanding the body and the functions of the various systems and the life processes like respiration through which the world gets energy to sustain life.
Yoga is also an art, the art of understanding our own body type with its own strengths, weaknesses, flexibilities and creating the right kind of environment for the body to stay healthy so it can connect well with the Supreme.
Yoga shows us the proper process of connecting to the Supreme and realizing his true nature. In present time, Yoga is misunderstood as a process of achieving just good health by performing physical postures, however, the original purpose of Yoga is to connect with God by controlling one’s body, mind and senses. Once these are all in harmony, good health automatically comes into being as “A healthy mind resides in a healthy body”.

Gita and Yoga:

Bhagavad Gita, the most popular Indian text is a dialogue between the supreme and a man in the
middle of the battlefield where Krishna represents the Supreme and Arjun represents an ordinary being
like us. Arjuna became the medium through which the knowledge of yoga is delivered to mankind.
The answers by Krishna to Arjun’s questions reveal the complete science of Yoga and it helps us become united with the Supreme in a deep subtle relationship. All 18 chapters of Srimad Bhagwad Gita ends with the word “Yoga” as every chapter explains a unique way of forming a link with the Supreme among all the Yogas, namely Gyan yoga(chapter 2), the path of knowledge karma yoga(chapter 3), the path of action dhyaan yoga(chapter 6), the path of meditation bhakti yoga(chapter 12). the path of devotion are considered to be the most prominent. Krishna explains the process of Yoga begins with learning how to control and balance one’s mind through meditation when the person practicing Yoga is free from material desires, he is said to be “Sthitpragya”.
Many verses of Gita point at attaining union through knowledge, self discipline, and practice. In the 28th verse of chapter 4 in Gita, the supreme lord says that Ashtanga yoga is considered as a yajna offered to the lord. Such aspirants should follow eight limbs:

yama( Don’ts)
niyama( Do’s)
Asana(perfection of posture)
Pranayama(control of vital power)
Pratyahara(control of senses)
Dharana( contemplation)
Dhyaana(concentration)
Samadhi(meditation)

apane juhvati pranam prane ‘panam tathapare pranapana-gati ruddhva pranayama-parayanah apare niyataharah pranan pranesu juhvati (Gita 4.29)
Shloka 4.29 explains about the yogis that attain union through pranayama.
Prana is one but it assumes five different forms:

Prana ( Respiration)
Apana ( Excretion)
Samana (Digestion)
Udana (Swallowing of food)
Vyana (circulation of blood)

All the body functions are performed by air called pranvayu. Even to lift a weight we need to hold our breath. Yoga is the science of balancing these Pranas to attain self realisation. It comes through practice as said by Krishna himself in Gita.
Shlokas 10 to 18 of Chapter 6 in Gita particularly focuses on Dhyaan yoga and is one of the limbs of ashtanga yoga. Dhyaan yoga involves concentration and meditation on a point of focus with the intention of knowing the absolute truth.
yogi yunjita satatam atmanam rahasi sthitah ekaki yata-cittatma nirasir aparigrahah ( Gita 6.10)
This verse in Gita says that a yogi tries to meditate keeping the mind and body in full control.
tatraikāgraṁ manaḥ kṛitvā yata-chittendriyakriyaḥ upaviśhyāsane yuñjyād yogam ātmaviśhuddhaye ( Gita 6.12)
samaṁ kāya-śhiro-grīvaṁ dhārayann achalaṁ sthiraḥ samprekṣhya nāsikāgraṁ svaṁ diśhaśh chānavalokayan (Gita 6.13)
The above two verses further emphasize on the need of concentrating and exercising complete control over the functioning of senses and mind. It also brings out the importance of keeping the postures correct while practicing yoga.
Yoga is often called a “Practice” and Gita beautifully brings out the importance of hard work through Abhyasa.
Shrī bhagavān uvācha
asanśhayaṁ mahā-bāho mano durnigrahaṁ chalam abhyāsena tu kaunteya vairāgyeṇa cha gṛihyate (Gita 6.35)
In this verse God tells us about the importance of trying through continuous practice. Making repeated efforts to attain some quality is called “Practice.”
Yoga is not just about postures, yoga costumes and mats, it’s much more than that. Let’s look at the dictionary meaning of yoga in the western countries. It says:
A set of physical and mental exercises that are intended to give control over the body and mind.
Well, we know that it’s beyond that. Yoga is the art of joining the self to the all pervading power through many different ways named as yoga practices.
Yoga is a prefect, positive action for our evolution, positive life and health on physical, mental and spiritual levels. Our natural state of mind is peaceful, without any disturbance but we are so much indulged in the outside world that we are unaware of what is already given to us by the Supreme.
Yoga and Bhagavad Gita both teach us to attain that natural state which is our true nature, to attain that peace which is naturally within us by moving our focus from the outside world to the inside where real real peace lies. Both are the path of practice of self control and leads us to realize who we really are at our core.