Very beautiful question, ( Yoga) means Union and unity , these are very popular terms but what is beyond. Connection of Individual to divine consciousness.We are energy body and cosmic energy is all around us. All the cycle. Water cycle or life cycle is a Karma charka or Karma Wheel.
What is Karma - any action which is done by senses. Mind which keep of generating 1000 and 1000 of thoughts all the times is an illusionary material and everything is on the earth is a nature or Atom..which you can only experience through senses.But there are things which is beyond to experience and those you can only experience under Mind your complete control and sense as well. Yoga is a way to perceive the higher perception beyond senses or Mind.but if you are not able to work on your body,mind,senses and effects of intellectual Siddhis, how do you think going to experince it.
Hatha Yoga - says - If you wish to attain liberation, Samadhi -- First work on Body so that you can let me control and work with it to reach higher goal.
Ashtanga Yoga says- If your mind and seneses are under complete control and then you can reach to experience higher consciousness.
Read more here - https://mantrayogameditation.org/understanding-the-basic-difference-between-hatha-and-ashtanga-yoga/
If you simply understand that there are things which we can experience through senses and they don't exist as an atom.. Example Love, Feeling, Emotion.. they are invisible social animal and they live within mind and heart. Same way with a normal life practice you can only experience, visible and keep the impression but if you wish to deal with divinity you need to choose a path that is Yog or Yoga.
Thank You
Sarvottam
https://mantrayogameditation.org
https://yogateachertrainingindia.org