The document provides an overview of DAO, ORM tools Hibernate, iBATIS, OJB and JPA. It discusses what each tool is, its features and advantages. A comparison table compares the tools on factors like simplicity, performance, dependence on SQL. Hibernate is recommended for object model driven environments that need automatic SQL generation. iBATIS is suitable when custom SQLs need to be created and maintained or for existing complex database schemas. JPA is intended for relational databases only.