I am trying to research the best possible way to achieve this using vba to execute a problem. Once data is entered into cell A1 I want to run a macro to take cell B1 and fill it with a Red Fill for instance (I will eventually enter in a more complicated macro later). I am wanting to in the future have a macro look at range A1:A300 and when any value within that range is has data fill range B1:B300 with Red (i.e if A5 has a value in it color B5 red). I just want the macro to run if data is entered into cell A1 and not have the code keep running every time any cell value is changed. I have seen codes like the one below but to my understanding they continuously run any time any value is changed in the sheet and do not make the program run faster but I am not sure about this.

Code:

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("A1")) Is Nothing Then Macro
End Sub