Allah is a false god dreamed up by a false teacher.
"Allah" means "God" in Arabic.
God, Allah, Jehovah, YHVH, are all the same deity. Whether the deity actually exists or not is the only question.
Thi sis made clear in sura 2 of Qur'an (and I see I deleted my notes file when I read Qur'an) but says something along the lines of "And we took from the people of the book (Jews) a covenant..." Meaning, they took the God of the Jews and began worshipping it, but in their own way.
Anyone saying Allah is somebody else is either ignorant or this, or deliberately lying.