Does anyone really know…? Or care?
The Holy Spirit is a Person, namely God, the Third Person of the Holy Trinity (the Others being the Father and the Son, Jesus Christ). The Holy Spirit is fully God just as the other Two Persons are. Think of water. Water can have three states of being: ice, liquid water and water vapor. Each is water while not being the other states (ice is not liquid water or water vapor and so on).
Grace is a gift that the Holy Spirit gives by which one comes to share in the life of God (Father, Son and Holy Spirit). The soul receives grace just as the body receives water. In both cases it is essential to life; for the soul, grace is essential to eternal life. If God is like water, then grace is a cup of that water, but this water never evaporates or decreases. It can, however, be thrown away by mortal sin.
Grace is given to us (and restored to us) through God, the Holy Spirit.
Cat Herder has it right.
Grace is an action of the Holy Spirit. Grace is the result of the Holy Spirit working in our lives. The Holy Spirit performs the action. Grace is the result of the action.
The Holy Spirit is God. Grace is a free and undeserved favor from God which helps us to respond to his call to adoption and to become partakers in his divine nature. Grace is participation in the life of God.
Paragraphs 1987 through 2016 in the catechism explain it well.
When I was a child we had a neighbor named Grace. Can’t say whether she was amazing or not, but she was a kind old lady. We liked her husband too. I didn’t know anything about the Holy Spirit since we didn’t attend church when I was a child. My dad didn’t believe in it. He would go hunting or fishing or tinker around the house on Sundays. He thought church was just a place to go to show off your nice clothes or fancy cars or whatever and he felt out of place because we had neither.
What the others said.
By the way, you are a Catholic and you don’t know the difference???
Good subject for apologetics. Has nothing to do with Catholic Traditions.