Aman is the fictional continent west of Middle-earth in J.R.R. Tolkien’s mythology.
Aman is the westernmost continent of Arda, Tolkien’s imagined world. It lies across the Great Sea from Middle-earth and is the home of Valinor, the realm where many of the Valar and Eldar lived. The name “Aman” is therefore broader than “Valinor”: Valinor is a region within Aman, not the continent’s entire name.
In the First Age, many Elves traveled from Middle-earth to Aman during the Great Journey. The Noldor later returned eastward in the rebellion led by Fëanor, an event that drives much of the history in The Silmarillion. Aman was removed from the physical world after the changing of the world, while the Straight Road remained available to certain beings.
Readers sometimes use Valinor when the precise geographical answer is Aman. That answer is understandable in context, but the question asks for the continent itself. Middle-earth and Aman are separate major land regions divided by the sea.