Arab
Arab is a word which refers to an ethnic group as well as a language group. In modern terms, an Arab is anyone of (1) Middle-Eastern descent and (2) has some facility in the Arabic language. Historically, the term was narrower, referring to only those from Arabia. There is a tendency among Westerners to regard all Arabs as Muslims, but this is incorrect, as there are some of Christian Arabs, as well as other-religioned Arabs: actor Danny Thomas was a Christian Arab; the Copts of Egypt are Christian Arabs. There is also many Jewish arabs, virtually all of whom were expelled from the various Islamic countries in Arabia in 1948, despite living in some countries in Arabia in some cases since the time of King Solomon.
The Modern Arabic language is a member of the Arabian Semitic stock (which includes Hebrew) of the Afro-Asiatic family of languages, and with the Berberic languages, display remarkable structural similarities.