Excel Formula is one of the best feature in Microsoft Excel, which makes Excel a very very rich application. There are so many useful built-in formulas available in Excel, which makes our work easier in Excel. For all the automated work, Excel Macro is not required. There are so many automated things can be done by using simple formulas in Excel. Formulas are simple text (With a Syntax) which is entered in to the Excel Worksheet Cells. So how computer will recognize whether it is a formula or simple text? Answer is simple.. every formula in Excel starts with Equal Sign (=).