Questions about using in-cell functions/formulas in spreadsheet software.
A worksheet function is a function or formula that is used within the spreadsheet of a spreadsheet program like excel or openoffice-calc. The function can be a user-defined function via vba or a program-ready function like
=vlookup(). These functions are used to perform simple or complex calculations with the data from the spreadsheet.
Examples of predefined functions for Excel may be found here.
In Excel further functions may be created at will. These are termed User Defined Functions or UDFs.