The word novel is defined by the Oxford Dictionary as “a fictitious prose narrative of book length, typically representing character and action with some degree of realism." Novels are works of fiction that can fall into many literary genres (mystery, dystopian, realistic, etc.). Novels generally describe human experiences and depict a series of events. Since novels are stories, they contain plot, characters, setting, and theme(s). Novels can be written from any point of view, and can have one or many narrators.

A novel might be referred to as a “pocket theater” because novels are forms of entertainment (like theater) and they are generally published as books, therefore they can fit in one’s pocket.

Some examples of famous novels are To Kill a Mockingbird by Harper Lee, Jane Eyre by Charlotte Bronte, The Catcher in the Rye by J. D. Salinger, and the Harry Potter Series by J. K. Rowling.

One important feature of a novel is that there are lots of characters and subplots.  Because the novel is longer than a short story, the author has time to develop ideas in more depth and tie together the stories of several characters into one, ultimately cohesive, unit.  The richness of the experience of a novel is to see how all the parts will unite to create the whole.  It is theatre because the language of the novel creates the scene and action in the reader's mind, but the experience can set aside and rejoined as often as the reader needs to.

Novels have characters and settings, and the author is telling a story with those characters.  What makes a novel pocket theater is that it usually has a complex and interesting plot.  You can put it in your pocket and take it with you, because the theater is in your head.  The novelist's job is to set the stage and describe the action.

What are the salient features of a novel, and why is it known as pocket theater?

I think that you will wind up with a great many responses to this particular question.  I believe that you will receive more feedback with varying details and, all of them taken together, could render some composite answer.  I would say that one of the most powerful features of the novel is the exploration into the individual self.  the probing into the individual, what composes the individual, the experiences that helps to define or make the individual are all part of the novel experience.  In my mind, this is why the novel can be considered "pocket theatre."  The ability to explore different aspects of self, different notions of the individual, and the probing of how individuals fare in different contexts are elements that help to explore what an individual is and what the human predicament is.  In the end, I think that this is what makes the novel so compelling an art form in that it explores much of what the human predicament consists of and by which definition is present.  The dramatic exploring of the individual is one of the most salient features of the novel, in my mind, and something that contributes to its overall features.