There is a large difference between classical and opera singers. Opera singers train for years in order to develop their art. Classical singers also train for years, but they do not train as opera singers. Opera is an entirely different style of music and it is done on a stage without amplification. There are opera singers who do classical music and vice versa. Classical singers present music that is rich and powerful, but it does not tell a story in the way opera does. It focuses on nuances and can be light or heavy. Classical singers do use amplification when necessary.