Temperature determines the hotness or coldness. The surface temperature of Canopus is 7350 K. The surface temperature of Vega is 9602 K. Because the surface temperature of Vega is greater than Canopus, Vega is hotter.
Brightness is determined by the star's magnitude. The apparent magnitude of Canopus is (-0.72) and that of Vega is (0.03). we know that, lesser the magnitude, brighter is the star. Hence, Canopus is brighter.
Vega is hotter but Canopus is brighter. This is because, brightness depends on the star's distance and size of the star as well other than the factor temperature.