Jesus instituted the Eucharist during the last supper. We saw how Jesus gave himself to us as the 'bread of life' and as 'living water'. In holy Mass, his sacrifice on the cross and his resurrection are represented again.
Holy Mass traditionally exists of two parts.
In the first part, we hear after the opening rites lectures from the bible. The first lecture is from the Old Testament. De second is from the epistles or from the acts of the apostles. The third is from the Gospel, the good tidings about Jesus Christ. On Sundays, there is also a sermon. After the second Vatican council, the liturgy of the word has become the largest part of Sunday Mass. Before the council, you weren't formally late if you entered the church during the confession of faith that is the conclusion of the liturgy of the word.
The second part begins with the preparation of the gifts, bread and wine. While holding his hands over these gifts, the priest says the words Jesus said during last supper. This is the most important moment of Mass. After the Lord's Prayer, the priest breaks the bread. The faithful recognize in him Jesus, just as the disciples did in Emmaus. Subsequently, everybody receives a little piece of this consecrated bread to eat it. After the final rites, everybody goes his own way.
In the old tridentine Mass, the priest turns his face to Our Lord in the pyx, and his back to the faithful.
The accent lies on the second part. All prayers and hymns are in Latin. The faitful receive the consecrated host on the tongue, kneeling at the communion rails.
I find this Mass even more beautiful than the new one, but we have to take precautions lest the faithful think, unjustly, these rites are magic.
Furthermore, a drawback of the old Mass is the faithful don't shake hands when the priest wishes them the peace of the Lord. Nowadays that's important, because in modern life we easily pass each other without any greeting.