Banking has changed in many ways through the centuries. The oldest forms of banking were often simple loans issued to businesses to purchase their goods. Once the goods were sold, the lender collected the money for the loan with interest. Today's banks have diversified their services and products, with the goal of providing fast and efficient service. By putting a community's surplus funds to work through deposits and investments, banks are able to assist individuals in purchasing cars and homes, start businesses, send children to college, and countless other advantages.

These activities conducted by the bank are divided into retail banking, business banking, corporate banking, private banking, and investment banking. While most banks operate as profit-making, private enterprises, some are owned by the government and considered non-profits. These banks might supervise commercial banks, oversee monetary policy, and act as a lender of last resort.

The definition for the various bank activities are defined below:

Retail Banking - deals directly with individuals and small businesses.

Business Banking - services which are provided to mid-market businesses

Corporate Banking - services designed for large business entities

Private Banking - offer services to private individuals possessing sizable assets

Investment Banking - relates to services on the financial markets (such as stocks and bonds)

Retail Banks Defined
The term commercial bank distinguishes it from an investment bank. Following the Great Depression, the U.S. Congress ordered banks to engage only in banking activities. Investment banks were confined to capital market activities, such as the stock and bond markets. As this separation is no longer mandatory, "commercial bank" indicates what people normally refer to as a bank. It can also refer to a financial institution that deals mostly with deposits and loans from large corporations.

Locally operated, community banks are generally created to empower employees to make decisions that serve the best interests of their clients and partners. Meanwhile, community development banks or CDBs are those designed to serve residents in low- to moderate-income areas, as well as spur economic growth. The retail bank products are designed for customers who are considered "financially underserved." CDBs exist in cities around the country, from Chicago and New Orleans to New York City and Washington, D.C.

Postal savings banks were offered by post offices for those who did not have a safe and convenient method for saving money. The United States began this system in the early 1900s to encourage saving among the poor. It was abolished in 1966. In Japan, one of the nation's leading bankers is the post office, which holds trillions of yen belonging to overly-conservative citizens.

Managing the assets of high net worth individuals, private banks originally defined banks that were not incorporated and owned by an individual or a general partner with limited partners. In this case, creditors could look at the entirety of the bank's assets, as well as the assets of the proprietor/general partners. Private banks have a long tradition in Switzerland, however most have since been incorporated.

Located in a typically low-tax jurisdiction, or tax haven, offshore banks are located outside the country of residence of the depositor. Some depositors seek the services of these banks for their easy access to deposits, less restrictive legal regulation, and increased privacy for the depositor. It is believed that as much as half of the world's capital flows through offshore centers. Swiss banks hold approximately 35 percent of the world's private and institutional funds, while the Cayman Islands, in terms of deposits, represent the fifth largest global banking center.

Specializing in accepting savings deposits and making mortgage loans, the savings and loan association are often mutually held, meaning the depositors and borrowers are members with voting rights. These rights allow them to direct the goals of the organization. Many fondly recall the old savings and loan run by George Bailey in the 1946 film It's a Wonderful Life.

Investment Banks Defined
Investment banks are concerned with helping companies and governments raise funds by issuing and selling securities in the capital markets. They also provide corporations advice on mergers and acquisitions, the trading of derivatives, commodity and equity securities, and underwrite stock and bond issues.

While merchant banks were traditionally banks that engaged in trade financing, today the term refers to banks which offer capital to firms in the form of shares rather than loans. While venture capital firms are concerned with immature, high-potential growth companies, merchant banks tend not to invest in new companies.

Retail and investment banking combined creates universal banks, also known as financial services companies, who engage in everything from commercial and retail lending to offshore banking to customers in other countries through its subsidiaries. Some big banks are diversified and engage in multiple activities, including bancassurance, or the sale of insurance products in a bank.