I was asked this question in an interview. My answer was as follows.
Spring makes Java/J2EE development easier, more efficient and more productive. Hibernate helps to get rid of complex and tedious data access code and reap the benefits of object oriented principles.
By blending spring with hibernate we can create scalable, robust, maintainable and database independent enterprise applications at lightning speed thus reduce time to market.
I am not satisfied with my answer as interviewer was expecting answer in business perspective and my answer was far away and has technical details.
Some of the key points I’d say is cost (it’s open source, which means no licensing fees), speed of application development (turnaround time from getting an idea to having a deliverable is much shorter compared to other frameworks), portability (you can move the application to any server and it will more likely than not just work out of the box), flexibility (making changes to business logic is quick and easy), maintainability (java has been around for a long time and probably will be around for much longer, finding developers to work on the project in the future won’t be that difficult as it is when using legacy code), stability (since the architecture is build upon a stable platform, downtime should not be an issue), scalability (if the userbase grows rapidly, moving to a cloud environment is straight forward, no extra cost changing the application)