What are Islam region?

Answer 1

Islam is not restricted to any one country or region.

I heard people say that Islam is the religion of Arabs when in fact Arabs make up 20% of the Muslims (or even less).

there are more Muslims in India than in Saudi Arabia and there are more Muslims in Indonesia than in India.

addition:

Muslims believe in one God and that Muhammad is one of God's messengers.

Muslims believe in God, his angels, his books, his messengers (including Jesus), the Day of Judgment, destiny.

This may explain the Muslim understanding of God:

112:1-4

Say: He is Allah, the One and Only;

Allah, the Eternal, Absolute;

He begetteth not, nor is He begotten;

And there is none like unto Him.

2:256

Allah - there is no god except Him, the Ever-Living, the Sustainer of all existence. Neither sleepiness overtakes Him nor sleep. To Him belongs whatever is in the heavens and whatever is on the earth. Who is it that can intercede with Him except by His permission? He knows what is before them and what is behind them, and they encompass not a thing of His knowledge except for what He wills. His Kursi (throne) extends over the heavens and the earth, and their preservation tires Him not. And He is the Most High, the Most Great.