According to the online encyclopedia Wikipedia, acting is "the work of an actor or actress, which is a person in theater, television, film, or any other storytelling medium who tells the story by portraying a character and, usually, speaking or singing the written text or play." From the earliest days of civilization, the oral tradition of storytelling was one way history was passed on among communities. Actors emerged as the most gifted of storytellers, and their talents have engaged audiences for centuries ever since.
In ancient Greece, the earliest theatrical productions utilized a group of speakers known as the chorus, to narrate and comment upon the story. According to legend, around 12 BC one member of the chorus named Thespis stepped out of the chorus and narrated the story as a separate character. As a result, actors are sometimes referred to as "thespians" in his honor.
As theater developed throughout the centuries, actors were expected to have exceptional speaking skills such as vocal projection, enunciation, and the ability to speak in character voices. In addition, they were required to have the physical stamina and skills that would be required for such things as dance or stage combat. Because early drama was written in verse, actors who could speak well and interpret the text were sought after, and acting companies would use some of their own veteran actors to train others in the ensemble.
As time went on, the style of writing in theater evolved. Plays were no longer written in verse, but rather were written to reflect natural speech and realistic (rather than dramatic) situations. Late 19th century playwrights such as Henrik Ibsen and Anton Chekhov wrote emotionally-charged modern plays, and actors needed to adapt their acting style and method of preparation in order to genuinely interpret the text. Konstantin Stanislavsky, a Russian actor in the company that performed many of Chekhov's plays, recognized this and developed a preparation method known today as the "Stanislavsky System" (often confused with "method acting," which is different) to help actors with the emotional and psychological preparation required to portray the more complex characters found in modern plays. Throughout the 20th century, many students of Stanislavsky and the Stanislavsky System went on to create professional schools of acting, many of which are still in operation today.
Today, actors work in many settings. The theater can include children's, amateur, professional, and regional settings, while modern media can include television, radio, film and web series portals such as YouTube. Professional actors sometimes belong to unions such as the Screen Actor's Guild as well as many other professional organizations.
College acting programs often include courses in the history of acting, voice diction studies, movement, scene study, and acting technique. We have homework help tutors familiar with these and many other acting-related subjects at the undergraduate and graduate level, so go ahead and submit!
Here's a handy guide to Script Annotation for Actors: