Theatre is a craft that has been around almost since the beginnings of human history. At its core, it is live storytelling, where the characters in the story (also called a play) are acted out by the people, called actors, who are bringing the story to its audience. The settings of the story are presented by constructions that are usually made of wood, paint, and canvas, called set-pieces. Sound and light are also used to create the world of the story, and a director is hired to show the actors how to tell that particular story.
A Little Bit of History...
It is thought that theatre began with ancient humans, who would act out tales from their lives around the evening cave-fire. These early 'plays' would have incorporated speech, music, dance, painting, indeed any skills or tools at hand that could be used to get the story across. Shamans used similar techniques when communicating the mythology of a culture to its people, as well as to invoke that mythology by calling upon its gods or powers in prayer. Along the way, fiction sprang from the forehead of mythology. The ancient Greeks wrote down their stories, fact, fiction, or otherwise, in what are the first recorded plays.
It is from ancient Greece that we get the term 'thespian'. Thespis was one of the first known playwrights, and was the equivalent in his age of a William Shakespeare, or Samuel Beckett1. He was also one of the first theatre teachers, passing the craft down to another generation. Hence actors, directors, set builders, all storytellers in this craft were known as Disciples of Thespis, or Thespians. Additionally, it is thought that there initially was no distinction between actors, director, and technical crew: all Thespians would have had knowledge of these things, a tradition that lasted until comparatively modern times. It was also the beginning of painted sets and constructed scene props, and the Deus Ex Machina - machinery that would move objects and cause actors to seem to fly, trap doors in the stage, etc. Performances were on stages in natural amphitheatres. The stories were huge, and included both heaven and earth in their scope.
When the Romans conquered Greece, they admired the theatre there. However, being Romans, they also thought they could improve upon it. This marked the advent of 'spectacle theatre'. In actuality, it really wasn't theatre at all: this was the start of the Gladitorial contests and public executions, chariot races, and bloody gore that we associate with Roman amphitheatres, and movies such as Ben-Hur and Spartacus. Theatre would have died, if not for the formation of travelling player troupes. These troupes, performing theatre that was considered too small, too unworthy for the higher people of society, travelled from town to town playing to the lower classes, to whom they owed their livelihood. These troupes spread across the known world and are the reason theatre still exists today
This was the state of theatre for hundreds of years. Thespians were simultaneously loved and hated by many. The Catholic Church in particular took a keen interest in the workings of the stage. Seeing such passion aroused in the audiences attending these plays, the church denounced all Thespians as Disciples of Satan, while at the same time commissioning their own players to bring Bible stories to the people. For about three hundred years, the Catholics held a monopoly on the stage. The end of this period coincided with the Renaissance, when permanent playhouses were erected. In the new spirit of learning, these playhouses were open to the public, and privately owned. Initially they showed the old Greek tales, and other stories that had been written for travelling player troupes, but then a new breed of playwright came forth, one that wrote to this new audience in this permanent playhouse setting. A revival of the Greek style of theatre was born. From here, the writing progressed to more human issues, and the theatre became a place where, even though they still didn't sit together, you would see nobles and peasants in the same building, watching the same stories unfold.
Enter the likes of William Shakespeare, Christopher Marlowe, and all their peers in the Elizabethan Age. This was the point where actors became actors, directors became directors, playwrights did their thing, and producers generally muddled it all up. This was the birth of what would eventually be known as 'modern theatre'. Every play you see today is put up using techniques and processes that originated with Shakespeare and his contemporaries. They've been revised and renewed on the macroscopic level several times over, but those people laid the foundation for all you see in the theatre today.
Modern productions range from the grandiose musicals, which incorporate song, dance, and orchestra to help tell the story to the pared down Black Box Theatre, which follows the 'less is more' approach to telling a story. Though those involved rarely share jobs in the manner of old, theatre is still a highly collaborative process. It's not about the director, or the actors, or the playwright, or the producer - it's about a story that is being brought to life.
How Do They Do That?
If you ask ten actors how they execute their craft, you'll get 15 different answers. The most commonly followed process, and the most highly revered, is known as 'the method'. It was first created in the 1920s by many actors and directors, the most well-known of which is Stanislavsky2, and has been pioneered for generations by Thespians such as Sanford Meisner, Marlon Brando, and David Mamet.
The 'method' is actually a catch-all phrase for a large number of techniques that all correspond to basically the same aim. It holds that the basis of any plot is action: what a character or group of characters is doing to get what they want, and to overcome any obstacles that may lie in the way of what they want. For example, nobody's going to be interested in a villain who's trying to appear villainous because he thinks it will make him look like a good actor. However, once we see Alan Rickman put a gun to Bruce Willis' wife's head in an effort to drive him out, the audience's attention is assured. The trick is to suspend disbelief. If Alan Rickman didn't believe what he was doing in that scene with Bruce Willis and his screen-wife, it would be just as boring as if he twirled his moustache and leered and grinned and tried to come off sounding witty. So the method is a process by which the actor can create believability in his or her character, and thereby serve the story's plot3.
As mentioned before, the actors are not the only members of a production. The director is the member who studies the play, dissects the plot for any recurring themes, figures out how to tell the story, and guides the actors in doing it. The production design team is just that: they design and build the costumes, set pieces, lighting, sound, and all the other 'neat titbits' that go into a play. The techies, or stage crew, are the ones that use and handle any equipment, such as pulleys, that fly out of set pieces, making sure that the lights actually work, running an electrical board to turn them on, running a sound board to actually make the sounds turn on when they're supposed to, getting the actors into costumes and so on. They are the ones that make things work behind the scenes. All these people work collaboratively to put on what the audience sees when they are sitting in that theatre.
'The Play's the Thing...'
Everybody thinks they know the stories of Hamlet, and Romeo and Juliet, Robinson Crusoe, David and Goliath, and scores of other stories, but being in an audience for a play is like being a part of the story itself, and watching life unfold. Anybody who's ever gathered around a street fight and cheered on one person fighting, or who's witnessed a domestic verbal sparring match in a crowded restaurant, or seen three or four people out in the fog suddenly laugh for no apparent reason can testify to this just as if they've seen a play before.
After all, 'The world is but a stage...'