EditCut
Edit Cut copies the selected text into CutBuffer, then deletes it from the text area.  The previous contents of CutBuffer are lost.

EditGrab
Edit Grab copies the selected text into CutBuffer, but does not delete it from the text area.  The previous contents of CutBuffer are lost.

EditPaste
Edit Paste copies CutBuffer into the text area at the location of the text cursor.  The contents of CutBuffer are not altered.

DeleteBuffer
The DeleteBuffer is a non-visible text storage area.  A copy of selected text is copied into DeleteBuffer whenever Edit Cut or Edit Buffer is executed.  Edit Insert copies the contents of DeleteBuffer into the text at the text cursor.

CutBuffer and DeleteBuffer are completely independent - operating on one has no effect on the other.

EditDelete
Edit Delete copies the selected text into DeleteBuffer, replacing its previous contents, then deletes the text from the text area.

EditBuffer
Edit Buffer copies the selected text into DeleteBuffer, replacing its previous contents.  Text is not deleted from the text area.

EditInsert
Edit Insert copies DeleteBuffer into the text area at the location of the text cursor.  The contents of DeleteBuffer is not altered.

EditErase
Edit Erase deletes the selected text without making a copy.  CutBuffer and DeleteBuffer are unchanged.  Think twice before you Edit Erase.   It may work alot like Edit Cut and Edit Delete, but the text Edit Erase deletes is irrevocably lost!