From an Islamic point of view, Allah is the special name of God and is the most precious name because it is not a descriptive name like other Ninety-nine names of Allah, but the name of God's own presence. It is impossible to alter the word in Arabic; such as create a plural form (gods) or change the gender. The Islamic concept of mankind's place in the universe hinges on the notion that Allah, or God, is the only true [reality]. There is nothing permanent other than God. Allah is considered eternal and "uncreated", whereas everything else in the universe is "created."
Muslims, when referring to the name, add the words "Subhanna wa Ta'ala" after it, meaning "Glorified and Exalted is He" as a sign of reverence. The entire religion of Islam is based on the idea of getting closer to Allah. Muslims consider Him eternal and uncreated, as the rest of existence was His creation. Although commonly referred to as a "He", Allah is genderless, but it is considered disrespectful to refer to Him as an "It."
Although the name "Allah" is most commonly associated with Islam, it was also used in pre-Islamic times. The father of Muhammad, Islam's prophet, had the name "Abdullah"; which translates to servant of Allah. The Arab Jews referred to God as Allah, and the Hebrew form of this name, El (אל) or Eloh (אלוה), was used as an Old Testament synonym for Yahweh (יהוה). The Aramaic word for God is also "Allah", therefore it is believed that Jesus Christ also used this word in his teachings.
Muslims believe that the name of Allah has existed since the time of Adam. The God in al-Islam is believed by Muslims to be the same God worshipped by Adam, Noah, Abraham, Moses, Jesus and Muhammad. According to Islam, Allah is the God of Abraham, and thus the Muslims claim to be followers of the same God of Judaism and Christianity.
Before the rise of Islam, the Nomadic tribes of the Arabian peninsula adopted Allah as the "creator God" who had lesser gods as partners, similar to the way Hindus regard Brahma, in a form of henotheism or polytheism. In those times, Allah was considered to be the ancestor and leader of the other gods, and people chose other gods and even idols to function as intercessors. Up until the seventh century, people would devote their worship to Allah's "partners"; other gods such as the goddesses al-Laat (اللات), al-Uzza (العزى) and Man'at (منواة), who were considered "daughters of Allah."
Muslims do not try to draw or depict Allah in any way, according to Islamic belief it could lead to idol worship. Instead, they focus on His 99 "Attributes that are stated in the Qur'an, the holy book of the Muslims. Nearly one third of the book is used describing Allah's attributes and actions. Also, "hadith qudsi" are special recorded sayings of Muhammad to Muslims where he quotes what Allah says to him. The 99 "Attributes are frequently written in calligraphic Arabic as a permissible decoration, which adorns mosques and homes of Muslims.
There are many phrases with Allah's name in it:
Here is an example of the name "Allah" written in simple Calligraphic Arabic: