A novel is a work of long prose fiction.
There are many types of novels. Novel is not a genre in itself, but rather a form. There are two main basic modes of writing: prose and poetry. A poem focuses on meter and language, and prose focuses on speaking-like sentences.
The main elements of a novel are the same as all prose fiction. They include characters and point of view, setting, plot, and theme. Novels also usually have chapters, and are significantly longer than short stories. This allows a novel to have more depth and complexity, more fully-developed characters and settings, and multiple themes.
Characters are the people who populate the novel. A novel will typically have one or more main characters, as well as secondary characters.
Point of view refers to how the story is narrated. This can include first person (I, me, my, we), third person limited (one perspective, he, she, them, names) and third person omniscient (same as limited, but with an all-knowing narrator).
Setting is where the story takes place. This consists of the time and place, but also includes local customs and traditions and time periods.
Plot refers to what happens in the novel. We describe plot as exposition (introduces the story), rising action (the problem develops), climax (the turning point), falling action (wrapping up), and resolution (ending).
Theme is the message of the story, or the moral. This is essentially the reason for telling the story, to explore human nature and deeper meanings.