Ever been guilty of using Excel as a fancy calculator? If so, you’d be just using a formula in Excel - such as =A1+A2 or =452*12.
So, you could write a formula containing a function eg. =MAX(A1:B20) or you could just write a simple formula which does not contain a function eg. =A1/A2.
Mastering the use of functions in formulas is a key skill in learning Financial Modelling. Happy formula-writing!