Unknown. Help us by suggesting a value. (Apple MacBook Air (2017) 13.3" Intel Core i7 2.2GHz / 8GB / 128GB)
Unknown. Help us by suggesting a value. (Apple MacBook Pro (2017) 13" with Touch Bar and Touch ID / Intel Core i5 3.1GHz / 8GB / 256GB)
VRAM (video RAM) is the dedicated memory of a graphics card. More VRAM generally allows you to run games at higher settings, especially for things like texture resolution.
VRAM: is this important to you?