Banks do many functions required by persons in their day to day life.
Banks help people by paying them interests by keeping their deposits.
They not only give loans to general people but also to the industrialists who run industries by charging them interest.
Banks works as a mediator between those who have surplus and who are in need.
Currently no substitute institutes or agency is there which can replace banks.
Banking business may get affected by cryptocurrencies like bitcoin etc. but they will definately overcome them by making adequate changes in banks technology or by reducing the bank charges.