Finance" is a broad term that describes two related activities: the study of how money is managed and the actual process of acquiring needed funds. The market's ability to sustain relatively large market orders without impacting the price of the security. This considers the overall level and breadth of open orders and usually refers to trading within an individual security. Market depth is closely related to liquidity and volume within a security, but does not mean that every stock showing a high volume of trades has good market depth. On any given day there may be an imbalance of orders large enough to create high volatility, even for stocks with the highest daily volumes. The decimalization of ticks on the major U.S. exchanges has been said to increase overall market depth, as evidenced by the decreased importance of market makers, a position needed in the past to prevent order imbalances. Because individuals, businesses and government entities all need funding to operate, the field is often separated into three sub-categories: personal finance, corporate finance and public finance.

All three categories are concerned with activities such as pursuing sound investments, obtaining low-cost credit, allocating funds for liabilities, and banking. Yet each has its own specific considerations. For example, individuals need to provision for retirement expenses, which means investing enough money during their working years and ensuring that their asset allocation fits their