function
A function is a predefined, named operation (such as SUM and AVERAGE) that you can use to perform a calculation. A function can be one of several elements in a formula, or it can be the only element in a formula. To use a function, you enter its name and, in parentheses following the name, you provide the arguments the function needs. Arguments specify the values the function will use when it performs its operations.
There are several categories of functions, ranging from financial functions that calculate interest rates, investment values, and other information to statistical functions that calculate averages, probabilities, standard deviations, and so on.