Every story needs structure and whether you are the writer or the reader, recognizing the story elements and the plot helps define the story, clarify the intention, retain focus, and create or follow the flow. There needs to be a theme and a plot and a satisfactory conclusion.
The rising action in a story includes any obstacles and conflict which exists in the story and which are essential to the plot. To distinguish between obstacles and conflict, consider that an obstacle is a stumbling block or a challenge (such as a disability or a language barrier, and so on) but a conflict is a rival (two friends competing against each other for the same prize, for example) or hostile force (it may be another person or it may be an inner struggle which threatens the main character's objectives.)
To help your child visualize the main components for the plot of a story, picture a triangular shape or imagine you are about to climb a mountain. Start at the bottom with the introduction (also called the exposition) where the main theme will be introduced (essentially, what is the story about?)
As you climb up the side of the mountain, you will explain the series of events or situations which naturally follow on from the introduction in a logical pattern. These represent the rising action and are the conflicts and obstacles which hamper the progress of the main character in the pursuit of his or her goals. The rising action leads to the most crucial point in the story.
At the top of the mountain is the climax (the most crucial point in the story) or the turning point. Perhaps up to this point everything has gone badly for the main character but a significant incident changes all that after which you will start down the mountain on the other side with the falling action as conflict begins to be resolved either in favor of or against your main character. Ultimately, you will reach the bottom of the mountain on the other side and the resolution (also called the denouement) will complete your story tidily and satisfactorily.
Hope this helps.