can someone explain to me the function of this macro. Thanks for your help

Sub INSONEEVERYTWOROWS()
Dim iLastRow As Long
Dim i As Long

iLastRow = Cells(Rows.Count, "N").End(xlUp).Row
iLastRow = iLastRow - (iLastRow Mod 2 = 0)
For i = iLastRow To 2 Step -2
Rows(i).Resize(1).Insert
Next i

End Sub