Arabic is an Aramaic language spoken throughout the Arab world and has been an important literary language for over 1500 years. The Koran, the holy book of Islam, is written in the Arabic language. Due to its close association with the Islam, Arabic spread rapidly throughout the Muslim world were today there are some 225,000,000 speakers of Arabic living around the world. The languages of Turkey, Iran, northern India, even Portugal and Spain, are replete with words borrowed directly from Arabic or formed with Arabic roots. It is important to note that while modern, spoken Arabic varies greatly from country to country, classical, literary Arabic has remained essentially the same over the centuries. The expression "Arabic" itself can be used to refer to either literary Arabic or to one of the many spoken varieties found around the Muslim world. Arabs tend to view spoken variations as mere dialects and consider only literary Arabic to be the true standard for their language. Arabic is also a Semitic language and a close relative of Hebrew.