The Hebrew Bible says that the Ark of the Covenant (Aron HaB’rit) was a container for both sets of stone tablets of the Ten Commandments.
There is some debate about what else was inside the Ark. Some scholars say that Aaron’s staff, a bowl of manna, and the first Torah scroll were in or next to the Ark.
According to the Bible, G-d commanded the Israelites to build the Ark. The Ark was a symbolic seat and physical manifestation of G-d’s presence. However, scholars debate why G-d ordered it built.
The Israelites carried the Ark in the desert for many years. Later, it was placed in the Holy of Holies in the First Temple. Only the High Priest was allowed to see it one day per year, on Yom Kippur. It is unknown what happened to the Ark after the destruction of the First Temple. This painting imagines how it might have looked with Moses praying before it.
Today, synagogues contain a Torah Ark which commemorates the Aron HaB’rit.
Text adapted from Simple English Wikipedia, Creative Commons Attribution-ShareAlike License 4.0.
Moses and Joshua in the Tabernacle, c. 1896-1902, by James Jacques Joseph Tissot; Jewish Museum, New York; Public Domain.