Media Glossary : Narrative Structure...

The term narrative was defined by David Bordwell as "a chain of even in cause-effect relationship occurring in time and space". Although causality (and time and space) is central to narrative, film also make use of different principles, such as parallelism (this is where two separate lines of actions are inter cut in order to allow the audience to compare and contrast the action). With network narrativesm which show parallel lines of action and conceal causal links are increasingly more popular within film. Narrative meaning is created by establishing that something is a part of a whole and usually that something is the cause of something else. It is usually combined with humans actions or events that affect human beings. Narrative Structure is generally described as the structural framework that underlies the order and manor which a narrative is presented to a reader. The narrative text structures are the plot and the setting. Within film as a structure narrative can be divided in three sections, which is referred to as the three-act structure, which are the set-up, conflict and resolution. Below is a video explaining the basic elements of a plot and narrative structure and also an outline of the three-act structure :

The Set-Up : This is where all the main characters and their basic situations are introduced, it contains the primary level of characterization, by starting to explore the characters backgrounds,  and personalities. Also within the set-up a problem is introduced in order to drive the story forward
The Conflict : This is the main action within the story, it begins with the catalysts in order to set things into motion, and is the part of the story where the characters go through major changes in their lives as a result of what is happening, it therefore allows for character development
The Resolution : This is where the character is forced to confront the issues that have arised during 'the conflict' sections, and therefore allows all the element of the story to come together and inevitably leads to the ending.