What is chorus?

Chorus means a combined community it mainly works on together.  The chorus is a group of characters who take part with the actors in the dialogues of a drama and expresses their sentiments in song at intervals when there is no character on the stage. Originally the Greek chorus was a group of dancers or singers who performed at religious festivals in honour of Bacchus, the god of wine. In tts continuation, a group of persons were introduced in drama to take part with the actors and to sing their sentiments when no actor was on the stage. The importance of chorus diminishes as the drama progresses. In Greek tragedies, the chorus takes part in the action of the play, comments on the action, and gives it a lyrical quality. 

it was conventionally present in the plays of Aeschylus, Sophocles and Euripides. According to Aristotle, “The chorus too should be regarded as one of the actors, it should be an integral part of the whole and take a share in the action.” But the chorus is not an integral part of the English drama. In modern plays chorus is rarely  used. Some modern plays include one or more characters to comment on the action and these characters are known as choral characters.