The programming language used to access relational databases. All SQL-capable databases support a common set of SQL commands though individual applications may have their own unique SQL features.

A language used to interrogate and process data in a relational database. Originally developed by IBM for its mainframes, all database systems designed for client/server environments support SQL. SQL commands can be used to interactively work with a database or can be embedded within a programming language to interface a database. Programming extensions to SQL have turned it into a full-blown database programming language and all major database management systems (DBMS) support the language.

A specialized language used to construct database queries and manipulate data help within relational databases.