Many people confound physical field with radiation or worst, they don’t know what the difference between these two terms is. Even worst, the vast majority of people out there have no idea what these mean … they have never heard these two terms.
Physical field (gravitational, electric, magnetic, electromagnetic etc) is one of the two forms of existence of matter, the other one is the substance. Radiation is one of the propagation modes of energy. Energy is a property of matter. Radiation can be mechanical, electromagnetic, and many other kinds. Mechanical radiation has different propagation speeds while electromechanical radiation travels in vacuum at the speed of light (approximately 300.000 km/s).