Finance is the science of funds management. The general areas of finance are business finance, personal finance, and public finance. Finance includes saving money and often includes lending money. The field of finance deals with the concepts of time, money and risk and how they are interrelated. It also deals with how money is spent and budgeted.

Finance works most basically through individuals and business organizations depositing money in a bank. The bank then lends the money out to other individuals or corporations for consumption or investment, and charges interest on the loans.

Loans have become increasingly packaged for resale, meaning that an investor buys the loan (debt) from a bank or directly from a corporation. Bonds are debt sold directly to investors from corporations, while that investor can then hold the debt and collect the interest or sell the debt on a secondary market. Banks are the main facilitators of funding through the provision of credit, although private equity, mutual funds, hedge funds, and other organizations have become important as they invest in various forms of debt. Financial assets, known as investments, are financially managed with careful attention to financial risk management to control financial risk. Financial instruments allow many forms of securitized assets to be traded on securities exchanges such as stock exchanges, including debt such as bonds as well as equity in publicly-traded corporations.

Central banks act as lenders of last resort and control the money supply, which affects the interest rates charged. As money supply increases, interest rates decrease.