Database schema

I just started to work in a company that uses ERPNext and I am replacing the guy who used to work here.
I compared database schema of two versions of ERP.
erpnext 7.0.42
frappe 7.0.30


erpnext 8.4.3
frappe 8.4.1

I compared tabAccount and there are different tables.
Did you make this changes. Or it may have been done by the guy who used to work to the company where I currently work.

Latest version’s account table schema