What is formula?

 mathematical relationship or rule expressed in symbols.

A formula is an expression which calculates the value of a cell

formula is like the governing equation that relates many parameters to a specific output and how they all together control the final value of that output ..so formula is like function in math  , the formula gets the values directly calculated whenever any of this parameters changes 

Une formule est une expression indiquant l'ordinateur quelle opération mathématique à effectuer sur une valeur spécifique

A formula is mathematical opération ofen used in spreadsheet programs, such Microsoft Excel, it allow us  to quickly make calculations and get totals of multiple cells, rows, ect...

A formula is an expression which calculates the value of a cell. Functions are predefined formulas and are already available in Excel

formula is used for slove problem easily.

A formula is an expression telling the computer what mathematical operation to perform upon a specific value

Rule expressed in symbols.