Question

What does the average function do in a spreadsheet?

Answer 1

It calculates the average of the range the function points at.

Example: A1 = 3, B1 = 2, C1 = 1
AVERAGE(A1:C1) = 2

Answer 2

Basically calculates the average of the values in the selected cells! to use it, just select the cells you want to find the average of and click on the average function from the menu or toolbar(varies with application like MS Excel or OOo Calc).