Why all are interfaces in JDBC

why all are interfaces in JDBC
If anybody knows the answer tell me plz

Because of encapsulation of major database functionality, such as running queries, processing results, and determining configuration information.
JDBC interfaces is like a plug, where u can plug in any database to your application by adding there respective JDBC Driver.
The JDBC Driver is a set of classes that implement the JDBC interfaces to process JDBC calls and return result sets to a Java application. Thats the magic of encapsulation, we just have to program to the interface rather than the implementation. The implementation might change regularly keeping the interface unchanged and hence our application.
The one of the suggestion of design patterns, is , program to an inteface and not to an implementation.

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regards
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