The formula is the expression which used to calculate the value of the cell.
and function is the inbuilt expression which available in excel. Formula and function make easy to calculate data, manipulate data and generate the report.
In this section, we learn about formula and function.
Here in cell A3, we are going to apply the formula. the formula always start with = sign we are going to add two values of cell A1 and A2
=A1+A2 is the formula

if you want to apply function for the same task we have a sum function lets see
the result is the same: sum is the predefined function and =A1+A2 is the formula which is created by us.

To enter formula:
1. Select cell in which you want to make formula
2. Start with =sigh and type A1+A2 or select A1 cell and press + sign and select on A2 cell
(note this is an example you can do anything -,/,* and many more)
3.and finally press enter
now if you change the value of cell A1 or A2 you result is also change.

Edit a formula :
to edit a formula
1 select cell where you apply the formula.
2. now type the new formula
3. press enter
see the results.

Use of two or more operator in the formula.
we have many tasks that we have to use one or more operator on same formula and function so we need to do same as insert formulas
1. select cell.