Valinor was Tolkien’s fictional paradise west of Middle-earth. It was the dwelling place of the Valar and many of the Eldar, within the larger realm of Aman.
Valinor included regions such as Valmar and the two Trees, Telperion and Laurelin, whose light preceded the Sun and Moon in Tolkien’s mythology. The destruction of the Trees became one of the central events of the First Age.
Aman is the continent or realm containing Valinor, so the two names are related but not identical. Númenor was a separate island kingdom, while Beleriand was a region of Middle-earth during the First Age. These distinctions help prevent common geographical mix-ups.