What is SQl ??
 

Please give me answer.

The most advance usage and great to observe that is
SQL Queries can be used to retrieve large amounts of
records from a database quickly and efficiently. Especially for a banking sector these type database are used.

SQL means Structured Query Language. This language is used to update, deleting and requesting information from databases. It is an ANSI and ISO standard language. SQL database is not static so it can be modified any time .
SQL divide into two classes.
(1) DML means Data Manipulation Language
(2) DDL me and Data Design language

SQL is a specialized language for updating, deleting, and requesting information from databases. SQL is an ANSI and ISO standard. SQL statements are used to perform tasks such as update data on a database, or retrieve data from a database.

Which *NOT ONE* single major relationtal database system follows exactly.

Every one of them has some quirks in what SQL is accepted. Some (notably SQL Server) allow you to change certain aspects to ANSI mode, but by default they aren't ANSI-compliant.