The Tabernacle was a semi-permanent structure, a sort of glorified tent, which God ordered Moses to build to house the Ark of the Covenant. It also served as the predecessor to the Temple in Jerusalem. Exodus 26 describes the Tabernacle’s design and construction, chapter 27 describes the altar and the outer court and the lamp oil, chapter 28 describes the priests’ vestments, chapter 29 describes the priests’ consecration ceremony, and chapter 30 describes other items that belonged inside the Tabernacle. Chapter 35 begins a long narrative on the Tabernacle’s actual construction; its heavy repetition of the instructions in the previous chapters indicates just how important all these details were not only to Moses and the Israelites, but to God Himself.
The Tabernacle was surrounded by an outer court where Israelites could come in (after properly purifying themselves) and have the priests sacrifice their offerings. The Tabernacle proper, or “the holy place” housed various sacred vessels, and only properly-purified priests could enter there. And even inside, there was a veil keeping the Ark of the Covenant out of their sight except for on special annual occasions.
Outer layer: outer courts
Middle layer: the holy place
Inner layer: the holy of holies