what is true earning of celebrities?

when I hear something like an special event paid 100 thousands to a singer, what does that really mean? does it mean that singer actually got paid 100T, or the event paid 100T to the entertainment company the singer is part of, and probably the entertainment company paid 20-30 percent to that singer. So, the singer earned 20-30T as income for the performance?

Let s say, some magazine says, a movie paid al pacino 10M. Does this mean al pacino earned 10M for acting in that movie? or it means, the movie paid 10M to the entertainment business that al pacino is from, and that entertainment company paid something like 3M to al pacino?

I hear things like singers and actors made some lousy contract with entertainment company and they end up earning only small fraction of the total revenue and they are only scaping by. So, being a celebrity is not as glamorous as people think it is.