Islam (Arabic: الإسلام, romanized: al-ʾIslām) is an Abrahamic monotheistic religion teaching that there is only one God (Allah) and that Muhammad is a messenger of God. It is the world's second-largest religion and the fastest-growing major religion, with over 1.9 billion followers, or 24.9% of the world's population, known as Muslims. Muslims believe that the Quran, the holy book of Islam, is the verbatim word of God revealed to Muhammad over a period of 23 years. The religion is based on the Five Pillars of Islam, which include the declaration of faith (Shahada), daily prayers (Salah), charity (Zakat), fasting during the month of Ramadan (Sawm), and the pilgrimage to Mecca (Hajj) at least once in a lifetime. Islam has a rich cultural and intellectual history, with significant contributions to various fields such as science, philosophy, and art. The term "Islam" means "submission" or "surrender" to the will of God. In Hebrew, Islam is referred to as אִסְלָם (Islam). In other relevant languages, Islam is called Islam in Spanish, Islam in French, Islam in German, Islam in Italian, and Islam in Portuguese.