Difference in type between using and not using Set keyword

Question

I just solved a problem I was having putting the \"Set\" keyword in a definition line but what I would like to know is \"why\" ?

Basically, I am doing this:

Answer 1

Set is used to assign a reference to an object, Let (or simple assignment) to assign the value of an object (if any)

  Dim a As Variant
  Set a = ActiveSheet.Cells(1)
  'TypeName(a) = Range, a now contains reference to the cell's range
  a = ActiveSheet.Cells(1)
  'TypeName(a) = Double or String, whatever is in the Cell, a contains the cell's value