Complex sentence: Orton is best known by his time in the WWF (World Wrestling Federation, now WWE) apart from the WWF, Orton wrestled for several promotions in the United States, Japan, and other countries.
Split into simpler sentences: Orton is best known by his time in the WWF (World Wrestling Federation, now WWE). Apart from the WWF, Orton wrestled for several promotions in the United States, Japan, and other countries.