Canali was founded in 1934 in Brianza, north of Milan, and is still run by the family. Corneliani dates from 1958 in Mantua, at the other end of Lombardy. Both built their names on Italian tailoring sold through department stores and their own boutiques, which is why they end up side by side in the same resale searches.
Neither house makes one kind of suit. Each has run several lines at different price points over the decades, and construction follows the price: some jackets are canvassed through the chest, others are partly or fully fused. So a claim that one brand is "full canvas" and the other is not tells you very little about the jacket in front of you.
The check is physical. Pinch the front of the jacket below the top button and pull the layers apart gently; a floating canvas lets you feel a separate third layer between the cloth and the lining. A fused front feels like one stiff sheet, and on older pieces it can bubble after dry cleaning, which is worth looking for in listing photos.
Shoulder shape also differs from line to line and era to era, so judge it from the photograph rather than the label. Look at where the sleeve meets the body: a clean, flat line suggests light padding, while a raised edge at the sleeve head signals a more built-up shoulder.
For cloth, trust the inside tags over the listing text. Italian suiting houses often print the mill name on a label or woven into the lining, and the composition tag settles whether you are paying for pure wool or a blend.
Because both brands spread across so many lines, their resale prices overlap heavily, and the label alone is a poor guide to value. A canvassed jacket in good cloth from either house is a better buy than a fused one from the other, whatever the brand premium in the asking price. Ask the seller for close photos of the inside labels and the front edge before committing.