Allah is the name of the one true God. Nothing else can be called Allah. The term has no plural or gender. This shows its uniqueness when compared with the word god. This shows its uniqueness when compared with the word god which can be made plural gods or feminine, goddess. The one true God is a reflection of the unique concept that Islam associates with God.
To a Muslim Allah is the Almighty, Creator and Sustainer of the universe, who is similar to nothing and nothing is comparable to Him. The Quran says: "Say (O Muhammad) He is God the One God, the Everlasting Refuge, who has not begotten, nor has been begotten, and equal to Him is not anyone".