Most Circassians are Sunni Muslim. The Circassians mainly speak the Circassian languages, a Northwest Caucasian dialect continuum with three main dialects and numerous sub-dialects. Many Circassians also speak Turkish, Russian, English, Arabic and Hebrew, having been exiled by Russia to lands of the Ottoman Empire, where the majority of them today live. About 800,000 Circassians remain in historical Circassia (the modern-day titular Circassian republics of Adygea, Kabardino-Balkaria and Karachay-Cherkessia as well as Krasnodar Krai and the southwestern parts of Stavropol Krai and Rostov Oblast), and others live in the Russian Federation outside these republics and krais. The 2010 Russian Census recorded 718,727 Circassians, of whom 516,826 are Kabardian, 124,835 are other Adyghe in Adygea, 73,184 are Cherkess and 3,882 Shapsug.
The Unrepresented Nations and Peoples Organization estimated in the early 1990s that there are as many as 3.7 million "ethnic Circassian" diaspora (in over 50 countries) outside the titular Circassian republics (meaning that only one in seven "ethnic Circassians" live in the homeland), and that, of these 3.7 million, more than 2 million live in Turkey, 300,000 in the Levant (mostly modern-day Jordan and Syria) and Mesopotamia and 50,000 in Western Europe and the United States.
The Circassians refer to themselves as Adyghe (also transliterated as Adyga, Adyge, Adygei, Adyghe, Attéghéi). The name is believed to derive from atté "height" to signify a mountaineer or a highlander, and ghéi "sea", signifying "a people dwelling and inhabiting a mountainous country near the sea coast", or "between two seas".
The exonym "Circassians" (// sər-KASS-ee-ənz) is occasionally applied to Adyghe and Abaza from the North Caucasus. The name Circassian represents a Latinisation of Siraces, the Greek name for the region, called Shirkess by Khazars and later Cherkess, the Turkic name for the Adyghe, and originated in the 15th century with medieval Genoese merchants and travellers to Circassia.
The Turkic peoples and Russians call the Adyghe Cherkess. Folk etymology usually explains the name Cherkess as "warrior cutter" or "soldier cutter", from the Turkish words çeri (soldier) and kesmek (to cut).