Watch these helpful resolution comparison tests made by DigitalFoundry. It’s no surprise that the PS4’s image quality benefits from things like higher-res textures and sharper dynamic lighting effects. View in HD for best results. For Xbox, take a look at this article.
The PS4 runs at a resolution of 1080p (1920×1080), while the PS3 runs below 720p (1024×624).
Beta Single Player Graphical Comparison
Beta Single Player Frame-rate Test