How to Make a Column Subtract the Respective Rows Cells

Hi All,

Im trying to make my F column show the totals in a subtract function from its respective rows E from D.

Example:

F5 would show the total from E5-D5.

F6 would show the total from E6-D6 and so on. I can get the function for each cell individually but I would like to know how to make that happen all the way down the sheet.

TIA!