The climax is a key point in the story where the main character reaches a determining point of success or failure. Rising action builds up to the climax, and the plot stage following the climax is called falling action. The climax essentially is the highest point of tension or energy in the story. Thus, the plot has nowhere to go but down after that.
Falling Action Details
The climax doesn't necessarily end all action, tension or resolutions to the story. However, it typically projects the direction of the story as it nears conclusion. After a main character dies, for instance, the story can't escalate in the same direction. Instead, those who loved him may mourn, and the author may present an impact he had on others. After a climactic battle, game or event, the story may finish with the joys of victory or disappointment the main characters experience.