2 cells same value, type is both

This reflects the change in A1 on Sheet1 on Sheet2:

Private Sub Worksheet_Change(ByVal Target As Range)

    If Intersect(Target, Range("A1")) Is Nothing Then Exit Sub

    On Error GoTo ErrorHandler
    Application.EnableEvents = False

    Sheets("Sheet2").Range("A1") = Target.Value

CleanExit:
    Application.EnableEvents = True
    Exit Sub

ErrorHandler:
    MsgBox Err & " - " & Err.Description
    GoTo CleanExit

End Sub

The code needs to go on Sheet1's code page so right click on the sheet tab and select View Code.

Similar code would have to go on Sheet2's code page changing the sheet reference in this line to Sheet1:

    Sheets("Sheet2").Range("A1") = Target.Value

Dom