SQL: Sub Queries

SQL Views are named saved queries that do not physically store data, acting as intelligent aliases for complex SELECT statements to simplify reuse. Conversely, subqueries are nested SQL queries where an internal SELECT provides results for an external query to filter or calculate data. Subqueries can be positioned within SELECT, FROM, or WHERE/HAVING clauses, with their behavior varying based on whether they return Scalar, Column, Row, or Table results for the final output.