The job of an actor or anctress is to impersonate a(in most cases)fictional character of sort. He or she might be performer on a theater or in silent movies. The most famous ones are at the top of society, but for the unknown name this a rather tricky way of making a living. One might be unemployed for moths before a job turns up...and when it comes the payment might not always be enough.
During the 1920s the film industry grows all over the world and the job opportunities are better than they ever were. Unfortunately this also means that the number of wannabies will increase in number.
The quality needed to be an actor is depending upon which part the entertainment business the actor happens to work in. Since films are without sound the main quality of a movie star is the looks while a theatre performer has to be a bit more articulated.