The English translates two unrelated Hebrew nouns:
The first is that of the vessel of three storeys in which Noah and his family and animals were accommodated during the Flood. This legend of Gen. 6–9 is similar to, and was perhaps influenced by, the Babylonian Gilgamesh epic which also features an enormous boat. The same Hebrew word is used for the basket in which the infant Moses was placed (Exod. 2: 3). This ark is referred to by 1 Pet. 3: 20–21 in the context of Christian baptism, which also saves through water.
The other noun denotes the Ark of the Covenant, a kind of portable shrine with a lid carried in the wilderness and round Jericho (Josh. 6) and supposedly containing the two tablets of the Law (Deut. 10: 2, 5). It was regarded as a throne for the earthly presence of the invisible God, and those who desecrated it were punished (1 Sam. 6: 19). It was once captured by the Philistines (1 Sam. 4) with disastrous consequences which led them to return it to Israel. The ark was established by David in Jerusalem and installed by Solomon in the Holy of Holies of his new Temple (1 Kgs. 8: 4–7). It was believed that its presence would protect the city from its foes, but in fact the ark was probably part of the loot when Jerusalem was destroyed by the Babylonians in 586 BCE. As the focus for the rite on the Day of Atonement the ark was held by later generations to be overlaid with gold (Exod. 25: 10–16). This is referred to by Heb. 9: 4, which implies that there existed another tradition that the ark also contained a portion of manna and Aaron's rod (Exod. 16: 33; Num. 17: 10).