* Statement : The Statement object is created by using
createStatement() method of Connection class. The Connection interface is the factory for Statement.
* PreparedStatement : The PrepareStatement object is created by using
prepareStatement() method of Connection class. It is used to execute the parameterized query.
* ResultSet : The object of ResultSet maintains a cursor pointing to a row of a table. Initially, cursor points before the first row. The
executeQuery() method of Statement interface returns the ResultSet object.
* ResultSetMetaData : The object of ResultSetMetaData interface cotains the information about the data (table) such as numer of columns, column name, column type, etc. The
getMetaData() method of ResultSet returns the object of ResultSetMetaData.