请教savepoint的问题

rheet1978

请教savepoint的问题
在看savepoint的解释的时候，对ON ROLLBACK RETAIN CURSORS和ON ROLLBACK RETAIN LOCKS不是很明白，这两个之间有什么区别？
另外，对这两个的解释也没看明白，不知道其英文到底想表达什么，每个词都能看懂，就是不理解：

ON ROLLBACK RETAIN CURSORS
Specifies system behavior upon rollback to this savepoint with respect to
open cursor statements processed after the SAVEPOINT statement. The
RETAIN CURSORS clause indicates that, whenever possible, the cursors
are unchanged by a rollback to savepoint. For situations where the cursors
are affected by the rollback to savepoint, see “ROLLBACK”.
ON ROLLBACK RETAIN LOCKS
Specifies system behavior upon rollback to this savepoint with respect to
locks acquired after the setting of the savepoint. Locks acquired since the
savepoint are not tracked and are not rolled back (released) on rollback to
the savepoint.