In the Scriptures, the ark was originally a golden chest designed to reside in the innermost chamber of the mishkan (tabernacle) and then later in the bet hamikdash (temple). This inner chamber was called the “Holy of Holies.” Inside the ark itself (sometimes called the ark of the covenant, the ark of the testimony, or simply the ark of God) were three things: the tablets with the Ten Commandments, Aaron’s rod that budded, and some manna (Heb. 9:4). On top of the ark was the kapporet (mercy seat) where during Yom Kippur the kohen gadol (high priest) would sprinkle blood between the outstretched wings of the cherubim to make atonement for the sins of the people.
In the modern synagogue, the Aron Hakodesh (holy ark) is the cabinet where sanctified Torah scrolls are stored. In most synagogues, the ark is an elaborate work of art, elevated off the floor and placed against the eastern wall (the direction of Jerusalem here in the west). During prayer, and especially when reciting the Amidah, the congregation faces the ark.
The ark is covered with a beautiful curtain called a parokhet, and over the ark usually hangs a special light called the ner tamid. In the Jewish liturgy, whenever the parokhet is opened or closed, a blessing is recited. In Orthodox synagogues, the parokhet is open and the scrolls removed only when there is a minyan (10 bar-mitzvah males) present.
In the bet keneset (synagogue), the aron kodesh takes the place of the Ark of the Covenant in the Temple. In front of the ark is the amud, or the platform upon which the cantor sings, and in front of the amud is the bimah, or torah reading table: