The One Ring is the object Sauron forges to control the other Rings of Power in J.R.R. Tolkien’s The Lord of the Rings.
Sauron creates the Ring in the fires of Mount Doom during the Second Age. He places much of his own power into it, allowing the Ring to dominate the other Rings and extend his influence over their bearers.
The Elves realize Sauron’s purpose and remove their Rings from his control. The One Ring nevertheless remains the key to Sauron’s power, so he searches for it after it is lost. Bilbo finds it long afterward, and Frodo inherits it.
The Ring of Barahir is an heirloom of Aragorn’s line, while Narya is one of the Three Elven Rings. A Silmaril is a different jewel from Tolkien’s earlier mythology.