This chapter introduces the reader to Structured QueryLanguage (SQL), which is a standard computer language foraccessing and manipulating databases. It is used by the useras a means of communication to the database managementsystem (DBMS). SQL commands consist of English-likestatements, which are used to query, insert, update, anddelete data. The chapter starts by describing the role andcharacteristics of SQL in a DBMS environment and how itevolved as a database language. The rest of the discussionis focussed on some of the most important and commonlyused SQL commands and queries.