This chapter serves as an introduction to the Handbook, as it lays the foundations of sociolinguistics as a subfield of linguistics, which is valuable in the theorising of language as a natural human faculty. The study of language variation and change has transcended sociolinguistics and is now of interest to syntacticians and phonologists as well. We present Arabic sociolinguistics as a direct descendent of general sociolinguistics, and in the European tradition, also of Arabic dialectology. We introduce the history of Arabic sociolinguistics and the important developments it has undergone throughout the last five decades.