Bascially If you read John 16:26, and John 15:26you’ll get a pretty good Idea…
But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:
Obviously the Holy Spirit is not the Father and not the Son and yet IS the Spirit of Truth which “shall teach you all things”…Such a Spirit of Truth capable of teaching All things (All Truth) must be a full partner in the Godhead…The thrid person of the One God.
This may not be the official explanation but it is how I view it.
Peace
James