ring (b) is pyranonse with β- glycosidic link
ring (a) is pyranonse with α- glycosidic link
ring (a) is furanonse with α- glycosidic link
ring (b) is furanonse with α- glycosidic link
Ring (a) is pyranose (six membered ring) whose anomeric C1 atom and α (below the plane) is joined with groups at C2 of ring (b) (furanose ring i.e., five membered ring)