"A stretched canvas is simply a canvas that has been stretched over a timber frame with mitred joints. A canvas panel is a canvas wrapped board. Canvas panels are much flatter, they can be framed and are a great option for quick projects, while canvases are larger in dimension and don't need to be framed.
Canvas panels are the perfect solution if you like the weave of a canvas but not the 'bounce' that you get when canvas is stretched on a stretcher bar frame. You can enjoy painting on a rigid surface that has the texture of your favourite primed or unprimed canvas by fixing it onto a wooden panel."
I have created many paintings on both.