Firstly, it introduced the concept of accessing many records with one single command.
Introduced in the 1970s, SQL offered two main advantages over older read–write APIs such as ISAM or VSAM. It is particularly useful in handling structured data, i.e., data incorporating relations among entities and variables. Structured Query Language ( SQL) ( / ˌ ɛ s ˌ k juː ˈ ɛ l/ ( listen) S-Q-L, sometimes / ˈ s iː k w əl/ 'sequel' for historical reasons), is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).
