Financial Transaction Account

A bank is a business that is based almost entirely on financial transactions. In addition to acting as lender for loans and mortgages, banks act as a borrower in a special type of loan called an account. The lender is known as a costumer and gives unspecified amounts of money to the bank for unspecified amounts of time.

The bank agrees to replay any amount in the account at any time and will pay small amounts of interest on the amount of money that the costumer leaves in the account for a certain period of time.

In addition, the bank guarantees that the money will not be stolen while it is in the account, and will reimburse the customer if it is. In return, the bank gets to use the money for other financial transactions as long they hold it.

Fonte: http://en.wikipedia.org/wiki