Hi Bill...
I don't know what you may exactly be looking for regarding communion, but we believe that the Lord is physically present in the bread and wine. The substance, if you will, is the bread and the wine. And that's what we see and taste. But the accidents, are in the bread and wine and are the body and blood of our Lord.
The priest, by the laying on of hands by the bishop, has the power to consecrate the bread and wine...
When he says the words, "This
is my body and this
is my blood...", that is when the bread and wine, contains both, the body and blood, in each of the species -- bread and wine. The actual conversion process, if you will, is known as "transubstantiation".
This is the Eucharist. Eucharist literally means, "thanksgiving".
I was raised in a fundamentalist Protestant home all my life, and I look back now, after my conversion, and I remember sitting in church and feeling like the "shot glasses", so to speak, were being passed around. It just didn't seem reverent to me.
I truly feel, that the strength of this feeling, hit me last year -- and it was my Lord, calling me home to the Catholic Church, where the Lord is physically present with us...
My life, my friend, has changed so much...
But anyway...

...I hope that answers your questions. Welcome to CF BTW...let us know if we can answer any more of your questions.