If D1 has a non-formula (text, number, date, TRUE/FALSE) and I use either
CTRL+D or CTRL+" in cell D2 I will get a copy of the value in D1

If D1 has a formula
--
Bernard Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme, the two give a different answer
If D1 has =A1, the in D1 the use of CTRL+D give =A2 which is what I would
get by dragging or copying D1 to D2
But CTRL+" will give =A1 ; so it gives an exact copy of what is in D1
without updating the cell references

best wishes

"AKMMS" wrote in message
...
And if there is a difference, what is it?

They both appear to copy the data from the cell above the selected cell.