I have an interview at a custodian bank, but don't understand what it is, or what:confused confused "technology and international network" the bank uses to make money. Also why do other banks use custodian banks, and is it not dodgy to be "moving financial assets around the globe"? How ethical is custodian banking compared to retail banking?

Thanks!

Custodian bank
From Wikipedia, the free encyclopedia
In finance, a custodian bank, or simply custodian, refers to a financial institution responsible for safeguarding a firm's or individual's financial assets. The role of a custodian in such a case would be the following: to hold in safekeeping assets such as equities and bonds, arrange settlement of any purchases and sales of such securities, collect information on and income from such assets (dividends in the case of equities and interest in the case of bonds), provide information on the underlying companies and their annual general meetings, manage cash transactions, perform foreign exchange transactions where required and provide regular reporting on all their activities to their clients. Custodian banks are often referred to as global custodians if they hold assets for their clients in multiple jurisdictions around the world, using their own local branches or other local custodian banks in each market to hold accounts for their underlying clients. Assets held in such a manner are typically owned by pension funds.