Irradiated foods are foods that are sterilized using x-rays or radioactive materials that kill bacteria. The process is called irradiation. It is used to remove germs from food. It does not make the food itself radioactive.
The benefits of irradiating food include the ability to control insects and bacteria, such as salmonella. The process can give foods (especially fruits and vegetables) a longer shelf life, and it reduces the risk of food poisoning.
Food irradiation is used in many countries. It was first approved in the U.S. to prevent sprouts on white potatoes, and to control insects on wheat and in certain spices and seasonings.