Published at LXer:
A function is a pre-defined calculation entered in a cell to help you analyze or manipulate data in a spreadsheet. All you have to do is add the arguments, and the calculation is automatically made for you. Beginners might be content to use Calc for lists, but, for advanced users, functions are the main reason for spreadsheets. If you understand functions, then you can start to use the real power of a spreadsheet.