ORM/Hibernate_1 tutorials-interduction to hibernate

-- -- WHAT IS ORM& WHAT IS HIBERNATE ?
---------ORM IS THE OBJECT RELATIONAL MODEL WHICH HELP YOU SAVE DATA INTO DATABASE(PERSISTANCY LAYER) IN OBJECT FORMAT...IN ORM S THERE ARE DIFFERENT TYPE OF OBJECT RELATIONAL MAODEL TOOLS IN THAT HIBERNATE IS ONE TOOL.....
TOPLINK ,MYBATIS,JDO,HIBERNATE,ORMLITE........or tool orm principle
-----------WE ALREDY HAVE JDBC Y WE HAVE TO GO FOR THE ORM ?
1.JDBC STORE DATA IN FORM OF VALUE IN JAVA EVERY THING WE HAVE DEAL WITH WITH OBJECT ..HIBERNATE ILL STORE DATE IN DATA BASE AND RETRIVE DATA FROM DATABASE INTERMS OBJECT ONLY..
(intrenally it uses the jdbc...)
no hits to databse will be incre due to which a burden on data base.....
what is a frame work really ?
........bailorplate logic prebuilted code
......... implemnets or to hibernate
benfits?