Data Definition Language :- It is a language udsed to define a data and their relationships to other types of data. Data definition language used to create file, database, data dictioneries and table within the database. DDL also define the format or scheme of the database.
Data definition language allows specification following information about the each table.
- Scheme for each table.
- Set of value associated with each attribute.
- The integrity constraints.
- Security and unthorization information for each table.
- Storage structure of each table on disk and othes storage devices.
Data manipulation language :- It is a language deals with the processing or manipulation of the database object. Dml provides for the program interface to open and close database, find recordes in the file, add new recordes and change or delete existing records.
Data Control Language :- Dcl is a language is used to impose security features and thus prevents unthorization access to data in the database. Security is provided by grating or revoking privileges on a user.