gibson and fender guitars

What is the difference between an Epiphone guitar and a Gibson guitar? (Or Squier and Fender)?
I’m just curious, is it the quality of wood used, or is it the type of electronics, and which one has the most effect on the tone?
battle of the corporations! just had to open that can of worm’s didn’t ya!
Well let’s see. Gibson along with Fender are the 2 biggest culprits of buying up smaller guitar company’s and trading there names in for cheap Chinese mass produced stuff, hence Squire Epi. so on, but dont laugh at some of the higher end Chinese stuff out there. it’s not bad. but it’s OK to snicker a bit when you see a (Spit) Squire
Winter NAMM SHOW 2010 – Gibson, Fender , Paul Reed Smith, Schecter, Batman Guitar, Highlights