Yes, radiators should be called 'convectors' - proportionally, very little energy is radiated.
An oven cooks by conduction - food is heated from the outside in, hence "cooked through".
Grills cook by a combination of conduction and radiation. The (proportionally) greater amount of energy radiated out by a grill, compared with, say, an oven, means that items will 'char' quickly. So that bread toasts, cheese melts and browns, and sausages turn black when I forget about them.
The 'glow' from a grill, whether gas or electric, is an indication that energy is being radiated.