The difference between a bank and a nonbanking financial institution (NBFI) is that

A bank interacts directly with the customers while an NBFI interacts with banks and governments.

A bank deals with both internal and international customers while an NBFI is mainly concerned with the finances of foreign companies.

A bank indulges in a number of activities relating to finance with a range of customers, while an NBFI is mainly concerned with the term loan needs of large enterprises.

A bank's main interest is to help in business transactions and savings/investment activities while an NBFI's main interest is in the stabilisation of the currency.