Canvas is a strong woven cloth traditionally used by artists to paint on and nowadays is also printed on.
Works on canvas need support which is provided by stretcher bars or board. Stretcher bars are 4 sections of wood similar to frame in which the mitred corners are joined and the canvas is stretched over it and stapled in place. Canvas on board is where the canvas has been glued to a thick board, usually of card.
There are 4 main ways to frame canvas art Standard Frame, Tray/ Floater/ L Frame, Mounted and St Ives, to read more, check out Fellows Framing website.