Simplify the following text for a Grade 12 native English-speaking person.
Original: When the league formed two conferences in 1974 , the cup transferred to the team that finished with the best regular season record in the Wales Conference , until 1981 , when the NHL changed its playoff format so that the two teams meeting in the Stanley Cup finals could no longer come from the same conference , and the Prince of Wales Trophy was presented to the Wales Conference playoff champions . By 1994 , the trophy was awarded to the Eastern Conference playoff champions .
Simplified: The Prince of Wales Trophy , or simply the Wales Trophy , is a National Hockey League ( NHL ) trophy awarded to the Eastern Conference ( formerly the Wales Conference ) playoff champions .