In order to avoid any confusion when dealing with contacts in OpenERP, we made some changes. The former structure (partner, address, contact) was too complex and so it wasn’t so suitable for handling situations like B2C, when you have to deal with individuals and not with companies.
How will this help you? In the first place, by eliminating res.partner address object there’s more clarity of who’s who. Before, it was difficult at times for users to understand what’s the difference between a partner and a contact, as not everyone you do business with can be called a partner, but on the reverse side, everyone is a contact.
More on: Simplified customer field in OpenERP