After reading most of the electromagnetism chapters of Feynman's lectures on physics, I would like to understand in more detail, at least an idea, of what causes the electromagnetic fields. Not sure where to go.
For instance, an electric field is caused by a charged particle. The presence of another particle would mean a force would act upon it. But is there a better explanation for this force to occur? By wikipedia browsing, photons are "the force carrier for the electromagnetic force". What does this mean exactly?