The Holy Sacrifice, "A Clean Oblation", "according to the order of Melchisedech" (Psalm of David 109, Second Tome of the Holy Douay Catholic Bible original English translation from Saint Jerome's Latin Vulgate original translation from the Hebrew/Greek original manuscripts)
The word "Mass" is from the Latin "missa", or missio, meaning "dismissal", from the fact that its two parts, that for the Catechumens (converts under instruction of the Faith in order to be baptized) and that for the faithful, were formerly terminated with a striking ceremony of dismissal. The sending away of the people at the end of the sacred function survives in the "Ite, missa est," i.e. "Go, the Mass is ended."

The Holy Sacrifice of the Mass is the unbloody sacrifice of the Body and Blood of Christ. It is substantially the same as the bloody sacrifice of the cross, and was instituted by Our Lord Jesus Christ at the Last Supper on the first Holy Thursday evening, just as He was entering upon His Passion. Then it was that He changed bread and wine into His most holy Body and Blood, and offered them in sacrifice, giving at the same time to His Apostles and their successors the power and the command to continue this sacred action in commemoration of Him to the end of time.

The picture above is of the altar and sanctuary. It is here that the Holy Sacrifice of the Mass is offered up which is The Way of Worship and Adoration to God of the New and Eternal Covenant. The picture to the right are the sacred vessels, Chalice and Appurtenances.
1. The Crucifix
2. Canopy or Throne of the Altar
3. Tabernacle covered by veil (wherever used the veil is of the color of the day or white)
4...9. Large Candlesticks (lighted only for High Mass and Benediction)
10...11. Small Candlesticks (lighted only for Low Mass)
12...14. Altar Cards (the larger is in the center, containing prayers which the priest reads at the Offertory and Canon. The smaller one on the Epistle side has the prayers read by the priest when washing his hands after the Offertory. The other smaller one on the Gospel side has the Gospel of St. John, which is read at the end of Mass)
15. First Gradine or Candlebench for the smaller Candlestick
16. Second Gradine or Candlebench for the larger Candlestick
17. Mensa or Altar Table
18. Altar Table Coverings (one wax and three linen cloths cover the altar table. The fourth or top one of linen frequently edged with lace hangs down over the side of the altar to the floor)
19. Antependium or Frontal (wherever customary a cloth of the color of the day hangs down in front of the altar)
20. Gospel Side of the Altar
21. Epistle Side of the Altar
22. Sanctuary Floor
23. First Altar Step
24. Second Altar Step
25. Predella or Altar Platform (sometimes called the Footpace)
26. Credence Table
27. Water and Wine Cruets
28. Finger Basin
29. Towel
30. Communion Paten
31. Sedilia or Priest's Bench
32. Bell
33. Communion Rail

On the right:
(a) Chalice - This is a cup made of gold or silver, or if of silver, the interior must be of gold. It holds the wine for the Holy Sacrifice, and is a striking figure of the Sacred Heart of Jesus.
(b) Purificator - This is a linen cloth used for wiping the chalice, and the fingers and mouth of the celebrant after Communion. It is spread over the cup of the chalice at the beginning and end of Mass.
(c) Paten - This is a plate of gold or silver upon which the large bread for consecration rests until the Offertory. Of old it was necessarily larger than now, for it held all the breads to be consecrated.
(d) Pall - This is a square pocket-shaped piece of linen with a cardboard inserted in order to stiffen it. It is placed over the chalice to prevent dust or other matter falling into it.
(e) Chalice Veil - This is the cloth which covers the chalice until the Offertory, and again after the Communion. It also is made of the same material and color as the vestments.
(f) Burse & Corporal - The Burse is a square container for the corporal when the latter is not in use. It is made of the same material and color as the vestments. The Corporal is a square piece of linen. In size and appearance it resembles a small napkin. It is spread out on the altar, and the chalice is placed upon it. During the Mass the Sacred Host rests for a time on the Corporal.