This chapter provides foundational knowledge about Arab-Americans, including their distinctiveness when compared to Arabs more broadly, their linguistic and cultural heterogeneity as a group, and the distinctive linguistic features of Arabic and diglossia. The author provides information on English-Arabic contrastive features and a listing of features in English language samples based on a standardized test with Arab-American children. The author emphasizes the need for professionals to employ critical thinking when evaluating the nature of many guidelines in serving Arab-Americans. This chapter presents a general overview of Arab-American history and the contributions of Arab-Americans. The author highlights that Arab immigrants to the United States have come from different communities that share commonalities but also have crucial differences in their experiences as Arabs living in the Arab world. This chapter aims to show that despite a shared identity as Arab-Americans, there exists great heterogeneity within this group, including differences that are often overlooked when Arabs in the United States and abroad are treated as one cohesive group.