What all are the difference between OpenERP and Odoo. I know Odoo(v8) is lastest version of OpenERP(v7) and also explain something about Odoo V9. Here difference in the sense it means what are all the additional feature available in Odoo and also about extra feature included in Odoo v9.
In OpenERP V7:
There have no any kind of website interface and E commerce faciality in this version so that the new territory comes in the market and new revolution for new API and also added new modules for Odoo 8.0
OpenERP V7 To Odoo 8.0
https://www.odoo.com/blog/odoo-news-5/post/odoo-8-release-notes-186
New Features for Odoo 8.0
http://www.nevprobusinesssolutions.com/top-12-odoo-8-features/
http://pragtechblog.blogspot.in/2014/04/openerp-8-features.html
For Odoo 9.0
By Febian Pianker
https://www.odoo.com/slides/slide/keynote-odoo-9-new-features-201
By netjunky
http://netjunky.net/odoo-9-new-features/
You can check for the above reference links to understand the OpenERP 7.0 To Odoo 8.0 To Odoo 9.0
I hope my answer may help you :)