This document discusses the different types of functions in Microsoft Excel 2003, including mathematical, statistical, financial, and database functions. Mathematical functions perform basic math operations like addition, subtraction, multiplication, and division. Statistical functions analyze data, including AVERAGE, MEDIAN, MODE, MIN, and MAX. Financial functions handle time-value-of-money calculations like FV, NPER, PV, RATE, and more. Database functions extract and manipulate data from databases, such as DSUM, DCOUNT, DGET, and DVAR.