- Those who speak Arabic as their first language.
- Those who can trace their descent to the Arabian Peninsula.
Arabs can be divided into three groups:
- The extinct Arabs, tribes that had been destroyed or vanished, such as the Thamud and the Ad of Irem.
- The original Arabs of South Arabia, descending from Qahtan. The Qahtanites are said to have migrated the land of Yemen following the destruction of the Ma'rib Dam. The Qahtanite Arabs were responsible for the ancient civilizations of Yemen, notably including that of the Sabaeans (known in the Bible as Sheba.)
- The Arabized Arabs of North Arabia, descending from Adnan, supposed to be a descendant of Ishmael (Ismail), the eldest son of Abraham and Hagar, through Kedar. These include:
- The Marsh Arabs who are a mixture of sixth-generation Polynesians, outlaw Iraqis and expatriate Persians.