Final answer:
In Excel, a prewritten or inbuilt formula is known as a function.
Step-by-step explanation:
In Excel, a prewritten or inbuilt formula is known as a function. Functions are predefined formulas that perform specific calculations and produce results. They can be used to perform a wide range of operations, such as mathematical calculations, logical tests, text manipulation, and more. For example, the SUM function adds up a range of numbers, the AVERAGE function calculates the average of a range of values, and the IF function evaluates a condition and returns a value based on the result.