How radiation occurs...

The radiant energy travels as a wave, like an x-ray or gamma ray, or as thermal energy. When you put your hand in an oven, one of the things that makes it feel hot is radiation. And this is the type of energy that makes a microwave work too!

There really isn't much more we can say about radiation right now that will help us cook our potato or egg. We'll just say that radiation is normally not important in cooking except for when you are using a microwave oven or a heat lamp to keep food warm.