Although Magento 2.x i.e in (2.0.5) had changes at File level some changes where made and can be observer in Database Schema also
Database Tables : 309
System Attributes : 130
1) In Magento 1.x we have table which start with core
core_resource (in which store the version number)
2) In Magento 2.x we are not using core any more
setup_module (in which store the version number)
authorization_role (Structure changed)
authorization_rule (Structure changed)
All tables related to customer “entity_type_id” had been removed.
May be more changes made in table structure so we will updating this post once if we found more.
Hope this will help you.