A commercial bank is a special type of financial company. Most provide checking, savings and other accounts for personal and business clients. In addition, many commercial banks offer business loans and credit cards. Most banks offer a variety of loans and are usually involved in personal, business, auto and home loans. Neighborhood banks are usually commercial banks because they offer checking and savings accounts as well as other commercial financial services. The firms make their money by providing loans and collecting fees that are associated with overdrafts, interest charges and credit card payments. Commercial banks are often involved in the real estate industry and may issue a letter of credit on a buyer's behalf. Having a letter of credit from a commercial bank is essential for buyers who wish to purchase real estate at an auction or other type of public sale. Some of the biggest commercial banks underwrite local bonds and engage in currency exchange.