The Torah describes in great detail the construction of the Mishkan, the portable Sanctuary. The ten-cubit by thirty-cubit Mishkan is placed within a fifty-cubit by one hundred-cubit courtyard. The Mishkan has two types of dividing curtains:
And you shall make a Partition (PAROCHET)of blue, purple and scarlet wool, and linen, twisted; of woven (CHOSHEV) work shall you make it, with cherubs. And you shall place it on four pillars of acacia wood overlaid with gold, their hooks of gold, upon four silver sockets. And you shall place the Partition under the clasps. You shall bring there, within the Partition, the Ark of the Testimony, and the Partition shall separate for you between the Holy and the Holy of Holies. … And you shall make a Screen (MASACH) for the opening of the tent of blue, purple and scarlet wool, and linen, twisted, of embroidered (ROKEM) work. And you shall make for the Screen five pillars of acacia wood and you shall overlay them with gold, their hooks of gold; and you shall cast for them five sockets of copper
(Shemot 26:31-33,36-37).

These two dividers ― the Parochet and Masach ― have much in common. They are made of the same combination of materials:
of blue, purple and scarlet wool, and linen, twisted.
Yalkut Shimoni (Pekudei 424) says that a thread of gold was intertwined with the other threads. Each measured ten cubits across and were ten cubits high (Barayta d’Melechet HaMishkan, Chapter 4).

Both the PAROCHET and the MASACH serve similar functions, in that they both create boundaries between different domains within the Mishkan. The PAROCHET divides the Mishkan into two areas: one third (ten cubits by ten cubits) is the Holy of Holies, where the Ark of the Testimony resides; the other two thirds (ten cubits by twenty cubits) is the Holy, the place of the Table, the Menorah and the Golden Incense Altar. The MASACH separates the Mishkan from the surrounding courtyard, where the Copper Sacrificial Altar was located.

A closer examination of these dividers, however, shows just how different they are from each other. The word PAROCHET derives from Peh-Resh-CHaf, which means to break or separate. The word MASACH comes from Samech-CHaf-CHaf (the same root that gives us SUKKAH, the thatched huts of the festival of Sukkot, as well as SECHACH, the thatching itself); it means to conceal or shield. It seems that the PAROCHET is designed to split one thing into parts, namely the Mishkan into the Holy and the Holy of Holies, whereas the purpose of the MASACH is to cut off the Mishkan from the area around it.

Rashi says (26:36) that MASACH is a door-curtain that covers the opening to the Mishkan. In his later comments to 35:12 he elaborates:
“anything that shields, whether from above or facing, is called MASACH or SECHACH, as in Have You not shielded (SACHTA) him? (Iyov 1:10) and Behold I screen (SACH) your way (Hoshea 2:8).
(See also Rashi on 40:3.) In contrast, says Rashi (26:31), the PAROCHET is a partition (mechitzah), what the Sages call PARGOD, a curtain:
“that which separates between the king and the people.”

There are three principal differences in the way these two curtains are made:
1. The PAROCHET is made of woven (CHOSHEV) work …, with cherubs, meaning that the cherub designs are woven into the fabric from both sides; whereas the MASACH is made of embroidered (ROKEM) work using a needle (see Rashi here, Yoma 72b and Rambam “Laws of the Sanctuary Vessels” 8:15).
2. The PAROCHET is held up by four acacia wood pillars, while the MASACH is supported by five pillars.
3. The PAROCHET is supported by silver sockets, but the MASACH is supported by copper sockets.

Keli Yekar (R. Ephraim Shlomo of Lunshitz, 1550-1619) explains the meaning behind these differences. It was forbidden to traverse the PAROCHET in order to enter the Holy of Holies, except when the Kohen Gadol performed the service on Yom Kippur. On that day, when all Israel deprives themselves of physical enjoyment, the focus of life is not on the material, but on pure cognition (MACHSHAVA), as reflected in woven (CHOSHEV) work. The whiteness of the silver sockets that support the PAROCHET symbolizes forgiveness and purity. And the Kohen Gadol ministers in four priestly garments, which is reminiscent of the four sockets. Keli Yakar concludes:
“One who sees this PAROCHET will contemplate and understand that he has no permission to enter there except when he resembles the cherubs.”

The MASACH, on the other hand, intervenes between the Mishkan and the courtyard, the place of the Altar. That Altar atones for all sins that are committed as a result of basic human weakness. The five sockets that support the MASACH correspond to the five senses, and the copper (NECHOSHET) of the sockets are suggestive of the snake (NACHASH) in the Garden of Eden. Man’s physical formation is symbolized by the embroidered (ROKEM) work:
My substance was not hidden from You, when I was made in secret; I was wrought (RUKKAMTI) in the lowest part of the earth (Tehillim 139:15).
In this way, the MASACH evokes the causes of sin: man’s physical nature, the luring of the Yetzer Hara, and the effects of the senses. Keli Yakar concludes:
“One who gazes upon the form of the MASACH will understand and know that, due to sin, permission is not given to everyone to gaze upon the place of holiness, as it is said:
Your transgressions have separated between you and your G-d (Yeshaiahu 59:2).”

The MASACH bars man at all times from approaching sanctity before cleansing himself of iniquity; the PAROCHET shows the way for man from holiness to even greater holiness, on the angelic day of Yom Kippur. The MASACH is a barrier; the PAROCHET is a transition,
“that which separates between the king and the people.”

The construction of the Mishkan serves as a constant reminder to us of the goals of our existence: first to become holy, and then to become holier still.