A bank is a credit institution that attracts money from individuals and legal entities for a fee. The funds accepted as a deposit are issued in the form of a loan to another client, who undertakes to return them within the period specified in the contract.
In this case, the borrower pays interest for the use of other people's money.
For example, an individual's deposit was placed at the rate of 7% per annum. A loan for the same amount was issued at 19% per annum. We get 12% of bank income.
Of these funds pay for the maintenance of the office, the salary of employees, but most falls into the bank's profits.
At this, the bank also receives money:
Stock market and securities
Earnings on currency exchange
Gold and coins
Bank fees
Penalties and fines