The Unique, The Single, The Only One.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is Al-Waahid (in Arabic: ٱلْوَٰحِدُ), the One and only God. There is no alternative. He is the sole originator from which all has arisen. He has no partners or relationships. None is equal to Him.
