To me, the cursor is the box that moves when you use the arrow keys plus derivatives and when you click on a cell and the cursor moves to the cell. Th cursor indicates the active cell.
The mouse pointer is the arrow or thick cross that follows the mouse movement.
I think “mouse cursor” is misleading. There should be “cursor” and “mouse pointer” as distinct items.
Also, if you have not remarked, the mouse pointer can be set to a thick cross for those who are excel nostalgic. Set this in Tools - Options - Libreoffice Calc - View - Visual Aids - Pointer and select “Themed” .