What are tuple variables in dbms?

Tuple variables in a Database Management System (DBMS) are used in relational algebra and query languages like SQL to refer to a specific row or record in a relation (table). They allow for the manipulation and retrieval of data by representing individual tuples while enabling operations such as selection, projection, and join. By using tuple variables, queries can be made more readable and structured, facilitating the expression of complex conditions and relationships among data.