Arabic is a Central Semitic language that first emerged in Iron Age northwestern Arabia and is now the lingua franca of the Arab world. It is named after the Arabs, a term initially used to describe peoples living from Mesopotamia in the east to the Anti-Lebanon mountains in the west, in northwestern Arabia, and in the Sinai peninsula. Arabic is classified as a macrolanguage comprising 30 modern varieties, including its standard form (Modern Standard Arabic).

Classical Arabic is the liturgical language of 1.7 billion Muslims and Modern Standard Arabic is one of six official languages of the United Nations. All varieties of Arabic combined are spoken by perhaps as many as 422 million speakers (native and non-native) in the Arab world, making it the fifth most spoken language in the world. Arabic is written with the Arabic alphabet, which is an abjad script and is written from right to left, although the spoken varieties are sometimes written in ASCII Latin from left to right with no standardized orthography.

Arabic usually designates one of three main variants: Classical Arabic, Modern Standard Arabic and colloquial or dialectal Arabic. Classical Arabic is the language found in the Quran, used from the period of Pre-Islamic Arabia to that of the Abbasid Caliphate. Theoretically, Classical Arabic is considered normative, according to the syntactic and grammatical norms laid down by classical grammarians (such as Sibawayh) and the vocabulary defined in classical dictionaries (such as the Lisān al-ʻArab). In practice, however, modern authors almost never write in pure Classical Arabic, instead using a literary language with its own grammatical norms and vocabulary, commonly known as Modern Standard Arabic (MSA).

MSA is the variety used in most current, printed Arabic publications, spoken by some of the Arabic media across North Africa, and the Middle East, and understood by most educated Arabic speakers. "Literary Arabic" and "Standard Arabic" (فُصْحَى fuṣḥá) are less strictly defined terms that may refer to Modern Standard Arabic or Classical Arabic.

The modern written language (Modern Standard Arabic) is derived from Classical Arabic. It is widely taught in schools and universities, and is used to varying degrees in workplaces, government, and the media. The two formal varieties are grouped together as Literary Arabic, which is the official language of 26 states and the liturgical language of Islam. Modern Standard Arabic largely follows the grammatical standards of Classical Arabic and uses much of the same vocabulary. However, it has discarded some grammatical constructions and vocabulary that no longer have any counterpart in the spoken varieties, and has adopted certain new constructions and vocabulary from the spoken varieties. Much of the new vocabulary is used to denote concepts that have arisen in the post-classical era, especially in modern times.

Classical Arabic is the liturgical language of 1.7 billion Muslims and Modern Standard Arabic is one of six official languages of the United Nations. All varieties of Arabic combined are spoken by perhaps as many as 422 million speakers (native and non-native) in the Arab world, making it the fifth most spoken language in the world. Arabic is written with the Arabic alphabet, which is an abjad script and is written from right to left, although the spoken varieties are sometimes written in ASCII Latin from left to right with no standardized orthography.

Colloquial or dialectal Arabic refers to the many national or regional varieties which constitute the everyday spoken language and evolved from Classical Arabic. Colloquial Arabic has many regional variants; geographically distant varieties usually differ enough to be mutually unintelligible, and some linguists consider them distinct languages. The varieties are typically unwritten. They are often used in informal spoken media, such as soap operas and talk shows, as well as occasionally in certain forms of written media such as poetry and printed advertising.