A bank is a financial institution licensed to receive deposits and make loans. Banks play an important role in the global economy, acting as a middleman between savers and borrowers and offering a host of services in addition to loans and savings programs.

In its most traditional form, a bank is a physical building where people interact with a teller and make deposits or withdraw money from their bank accounts. Nowadays, most people access their accounts through digital banking platforms, giving users the ability to transfer money, pay bills, and more - often without ever setting foot inside a physical building.

Banks are typically divided into three distinct types: retail banks, commercial banks, and investment banks. Retail banks often serve customers at the local level in one or multiple branches, and offer a variety of services, typically including savings, loans (personal, home, auto, etc) and other banking services such as checking, money market accounts and debit cards.

In contrast, commercial banks tend to focus on providing loans, credit and other services to small businesses and large companies. Investment banks, on the other hand, provide advice and services relating to underwriting debt, mergers and acquisitions, and often provide trading services.

Banks are generally regulated by the central government or central bank of the country they operate in; in the United States, banks are regulated by the Federal Reserve. Banking regulations vary from country to country and are meant to ensure that the financial system is safe and secure by requiring banks to hold a certain amount of capital and adhere to certain risk management practices.

Banks play an important role in the global economy. They facilitate the efficient flow of funds between savers and borrowers, and offer a variety of services to their customers, making it easier for individuals and businesses to access funds, invest, and grow. Banks must balance the need for safety and soundness with the need for innovation and growth, playing a crucial role in economic development.