Die Sonne gewinnen！
I think it's easy to understand what is JDBC used for.
Programer's program should be connected to DB.So programer need JDBC to make it easy.
JDBC is a standard interface which is achieved by the manufacturer.
A standard can make thing easy.
What should programer do?
just use the interface.
Drive Management:
Driver Manager
Connect Interface:
Connection
DatabaseMetaData
Sentence Object Interface:
Statement
PreparedStatement
CallableStatement
Results Interface:
ResultSet
ResultSetMetaData
JDBC's workflow:
1 load the driver,and establish the connection.
2 establish sentance object.
3 execute SQL.
4 deal with results' collection.
5 close connection.
Examples:my two other articles.