Yes, it is true that all sources of electromagnetic waves or radiation are also sources of the electromagnetic field or force. The electromagnetic field is a fundamental physical entity that exists around electrically charged particles or objects in motion. When these charged particles accelerate or oscillate, they create disturbances in the electromagnetic field, resulting in the propagation of electromagnetic waves.
Electromagnetic waves are formed by the oscillation and propagation of electric and magnetic fields, which are interconnected and self-sustaining. As the electric field changes, it generates a magnetic field, and as the magnetic field changes, it generates an electric field. This continuous interplay between the electric and magnetic fields allows electromagnetic waves to propagate through space.
Any source of electromagnetic waves, such as an antenna, a light bulb, or an electron in motion, is associated with an electromagnetic field. The field extends around the source, and as the waves radiate away from it, the electromagnetic field also extends throughout space.
However, it's important to note that while all sources of electromagnetic waves are sources of the electromagnetic field, the reverse is not necessarily true. Not all sources of electromagnetic fields produce detectable electromagnetic waves. For example, a static electric or magnetic field, such as that produced by a charged object at rest or a permanent magnet, does not generate propagating electromagnetic waves. These static fields do exist in the vicinity of the source but do not exhibit the wave-like behavior of electromagnetic radiation.