Can not understand this python inheritance example

Question

https://code.sololearn.com/cN6U2isR3XNT/?ref=app
Program is about
->Class BankInfo for storing fname, lname, gender, address
->Class BankAccount for storing account number and amount
->Class saving and current have two method interest calculate, validate, view profile

1) In this code when we create object of saving and current class why we pass class bankinfo object

2) and the method view profile in saving and current class how this work
Self.bankinfo.fname???