Allah is the proper name applied to the true God who exists necessarily by Himself comprising all the excellent Divine names and attributes of perfection. Allah is One and Unique. He has no son, no partner, nor equal. He is the sole Creator and Sustainer of the universe. Every creature bears witness to His Oneness, Divinity, andRububiyyah [inf. of Rabb], and to the uniqueness of His Attributes and Names.
The importance of this topic is directly related to the importance of Tawheed (Islamic monotheism) and the perfection of Tawheed in one's life and actions. As a scholar of old said that whoever does not know where His Creator is does not worship Him.