The way I've understood it is, particles are localized excitations of fields. You know of the Higgs boson. It is the excitation of the Higgs field, which exists through all space. Similarly, an electron is an excitation of the electron field (not electromagnetic field), which exists through all space. Every single electron is a localized excitation of the same, single field.
I don't know how to answer the relativistic questions of fields yet. For that one would need to learn a lot of Quantum Field Theory.
For the layman, however, these two links are very informative:
I don't know how to answer the relativistic questions of fields yet. For that one would need to learn a lot of Quantum Field Theory.
For the layman, however, these two links are very informative:
http://www.symmetrymagazine.org/article/july-2013/real-talk-... http://www.pbs.org/wgbh/nova/blogs/physics/2013/08/the-good-...