What happens during the Sacrament of the Eucharist?

-During the Sacrament of the Eucharist the Catholic person receiving holy communion receives physically and spiritually the Body and Blood of Jesus Christ.
-The bread and the wine (sacramentals) represent physically the Body and Blood of Christ. A word
used to describe this is transubstantiation which is the action of changing the bread and wine into the Body and Blood of Jesus Christ.

So Jesus blessed bread, broke it saying, "Take, eat; this is my body." Then he did the same with the cup of wine saying, "Drink from it, all of you; for this is the blood of my covenant, which is poured out for many for the forgiveness of sins." (Matthew 26: 26-28).