city} may have one or more banks. A bank is a financial institution that is charged with the function of accepting deposits and lending out money. Thus, it acts as an intermediary connecting individuals with a capital deficit with individuals having a capital surplus. Most banks have national and regional headquarters, and then branches in smaller towns and villages. The banks may be international, national or local in spread of operations. Banks, by virtue of their functions, are centrally placed in the financial system for most economies. Thus, their health is a crticial factor in maintaining the economic health of the country or the region. To ensure their solvency, banks function under a well-defined set of regulations. Most operate under the fractional reserve banking system, whereby they hold a small fraction of the money that comes in by way of deposits, and lends out the rest at interestes higher than the deposit rates, to earn a profit. Somerville may have one bank, or a number of bank branches. Some of the types of banks that may be present in Somerville are community banks, community development banks, credit unions, postal savings banks, private banks, and internet-only banks. One can both deposit money in these, as well as take out loans for a specified rate of interest and duration.