Answer:
Epiphone guitars are authorized and professional copies of Gibson guitars. These replicas are sometimes very close to the real thing, but then, sometimes they are way off. Although, today, a new Epiphone is the closest you can get to a Gibson. It's almost the same construction-wise and even tone-wise. Don't expect it to sound like, feel like, and be a Gibson for about 20% of the price of a real Gibson, though. They are not bad at all, but for the price, it might be worth looking into some older, cheaper used Gibsons, or older Japanese copies like Tokai or Burny. They are even closer to a real Gibson, and are - usually - way better instruments than any Epiphone guitars.