The proper name of God in Islam and in Arabic, referring to all of His perfect attributes at once. This name is a proper noun, and no other entity or being is allowed to have this specific name.
Allah is the All-Knowing, All-Powerful, and All-Merciful. Allah is the Creator and Sustainer of the universe and everything in it. Allah has no body, face, or physical form. Allah exists eternally and is limitless in all aspects (space, time, etc).
Allah’s essence can never be fully understood by human beings. The closest understanding that we can achieve is through Allah’s attributes, the most famous of which are the Asma al-Ḥusna – the Beautiful Names and Attributes of Allah.
Allah is the same name by which even non-Muslim Arabic speakers, such as Christians, refer to God.
Believing in Allah as the only God is the most fundamental pillar in the practice of Islam.