A soliloquy is a device used in drama where a character addresses the audience to portray an internal thought. The soliloquy can sometimes be confused with the monologue, however, the soliloquy is only to the audience and no other character is supposed to hear. A monologue is different because it is a dramatic speech to the audience and to other characters. When you watch this video, notice the similarities and differences in each actor's performance. Dialogue is crucial in dramas, which is why plays are viewed more on the content and less on the performance. Good plays can be performed badly, but bad plays can never be good because they suffer from poor dialogue.
Assignment: Shakespeare utilized the soliloquy and monologue often in his work. Post in the comments section another famous soliloquy or monologue by Shakespeare.