Generally database management system has three components. These are as follows
1. Data definition language
2. Data manipulation language
3. Data dictionary
Data definition language
The data definition language is the formal language programmers use to specify the content and structure of the database.
Data manipulation language
A data manipulation language is used in conjunction with some conventional application programming 
languages to manipulate the data in the database. The most common example is structured Query Language.
languages to manipulate the data in the database. The most common example is structured Query Language. Data dictionary
Data dictionary is an automated or manual file that stores definitions of data elements and data characteristics.
