Who is a Yogi? Most of us think that a yogi is one who usually does Yoga and things related to meditation..Right ? 
But in real sense A Yogi is not only a person who indulges himself in yoga or something like that, moreover, a yogi is a true being in himself, the one who is free from any boundries, the one who seeks for the supreme light of God, the one who burn himself just to light the life of other human beings. 
After I completed my novel #Yogi (Autobiography of a Yogi by Yogananda Paramhansa) i Got to know the real meaning of this pious word. According to the novel, 

A yogi must be able to pass into, and continue in, the super consciousness, regardless of multitudinous distractions never absent from this earth. Whether in the buzz of insects or the pervasive glare of the daylight, the testimony of the senses must be barred. Sound and sight come then indeed, but to worlds fairer than the banished Eden.

A true Yogi may remain dutifully in the world; there he is like butter on water, and not like the easily- diluted milk of unchurned and indisciplined humanity. To fulfill one’s earthly responsibilities is indeed the higher path, provided the yogi, maintains a mental uninvolvement with ego logistical desires, plays his part as willing instrument of God.

However, the titled has been named as Adiyogi, so you must be thinking who is he actually? 
When I was actually going deeper in the novel Yogi at the same time I got a chance to visit Adiyogi’s bust statue (AT ISHA YOGA CENTRE, Coimbatore , India) . After visiting there i was so cherished and overwhelmed by the energy of Adiyogi that I couldn’t express here in my Blog. 
So as I was writing about Adiyogi, he is the first ever yogi existed on this earth, basically known as Shiva.In yoga, Shiva is not seen as a God, but as the first yogi, Adiyogi, and the first Guru, the Adi Guru.

Here I m putting a poem written by Sadhguru on Adiyogi to conclude this whole topic: 

A quiet Sea
A quiet Day
A quiet Mind

But a raging Heart
Blazing with Fire
Of an ancient Sage.

Burning for many a millennia
Destructive for the ignorant
Enlightening for the seeking
Brutal to the stubborn
Tender to the willing.

When all the tricks fall
The First Yogi’s Fire shall
Burn the ignorant pall
To light the future’s citadel

Citadels of future are first
built in the minds of Ignorance or Light

These citadels when lit with Grace
Of the Blue-Bodied Maker of all race

Will be a worthy place to dwell here
and a passage to the ways of the beyond.

O’ how fortunate are we
To carry the Fire of the Adi Yogi.

:)