The difference of the database structure between Magento 2 and Magento 1.x.
Number of Table and Attribute
Module register table
In Magento 1.x, we all know that the module register table is core_resource. But this table can’t find in Magento 2, it was removed. Instead, when we look through the table in Magento2 database or read some PHP code to register module, we will find the new table is setup_module and it have structure same as core_resouce.
Name change for some tables