There seem to be confusion about the processes resulting in emitting radiation and sources of light - i.e., the objects where the light comes from.
The processes are any processes involving interaction between particles, coupling them to electromagnetic field. E.g., interactions between electrons and protons may result in emission of light - whether the electrons and protons are existing in a form of atoms, or molecules, or forming a crystal, collide in plasma or particle accelerator, etc.
Interactions within nuclei may also produce photons, but these are usually in the gamma range, i.e., these are usually not called light - which usually refers to the visible spectrum or nearby regions (like infrared and ultraviolet.) - see Electromagnetic spectrum and Do nuclei emit photons?.
Light sources: black bodies etc.
This light does not necessarily comes towards us directly - it may wander around and be re-emitted, reflected, scattered, etc. E.g., light in thermal equilibrium is referred to black-body radiation, and the objects emitting black body spectrum are often referred to as sources of light - in the sense that this is where we see the light coming from. However, the processes producing photons within these black bodies are the same that I mentioned above - mostly electromagnetic and nuclear interactions between particles.
How does radiation become black-body radiation?
Black body vs. Thermal radiation
Does fire emit black-body radiation?
How is light emitted by an incandescent lamp?
Remark: A mundane analogy is asking whether hot water comes from a teapot - yes, because it is heated in the pot, but no, because this is not where water originates.