Issue w/ electric field definition

[FOIWATER]

"an electric field is the region of space surrounding electrically charged particles and time-varying magnetic fields"

Why do the fields need to be time varying?

Additionally, if light is a frequency of electromagnetic radiation, and EM is made of magnetic and electric fields occurring at right angles to one another, is that what light is made up of? electric and magnetic fields?... obviously it's more complicated but what am I missing.

 

[earlofwessex]

you are missing quantum mechanics!

an electric field is a vector field of electric potential, and you get potential with charged particles. you also get potential with moving magnetic fields, as per faradays law (or is it amperes law?). i think the "and" in your quote could be replaced by "or" and retain its meaning.

as far as light goes, see this thread, or quantum theory