The Arab world (Arabic: العالم العربي al-ʿālam al-ʿarabī; formally: Arab homeland, الوطن العربي al-waṭan al-ʿarabī), also known as the Arab nation (الأمة العربية al-ummah al-ʿarabīyyah) or the Arab states, currently consists of the 22 Arab countries of the Arab League. These Arab states occupy an area stretching from the Atlantic Ocean in the west to the Arabian Sea in the east, and from the Mediterranean Sea in the north to the Horn of Africa and the Indian Ocean in the southeast. The contemporary Arab world has a combined population of around 422 million inhabitants, over half of whom are under 25 years of age.
In the Middle Ages, the Arab world was synonymous with the historic Arab empires and caliphates. Arab nationalism arose in the second half of the 19th century along with other nationalist movements within the Ottoman Empire. The Arab League was formed in 1945 to represent the interests of Arab people and especially to pursue the political unification of the Arab countries; a project known as Pan-Arabism.
The linguistic and political denotation inherent in the term Arab is generally dominant over genealogical considerations. In Arab states, Modern Standard Arabic is the only language used by the government. The language of an individual nation is called Darija, which means "everyday/colloquial language." Darija shares the majority of its vocabulary with standard Arabic, but it also significantly borrows from Berber (Tamazight) substrates, as well as extensively from French, the language of the historical colonial occupier of the Maghreb. Darija is spoken and, to various extents, mutually understood in the Maghreb countries, especially Morocco, Algeria, and Tunisia, but it is unintelligible to speakers of other Arabic dialects, mainly for those in Egypt and the Middle East.
The Arab League is a regional organisation that aims (among other things) to consider in a general way the affairs and interests of the Arab countries and sets out the following definition of an Arab: