The plot sequence of most short stories involves six major steps. The three steps you mention are but part of the picture. 1)The exposition of the story is information relayed to the reader about events that have occurred prior to the action of the story. This information is necessary to understand the conflict and other events that take place. 2)The conflict is the major problem (althought there may be other smaller problems) that drives the action of the story. 3)The rising action are events that take place in the story as a result of or in response to the conflict. These events raise the reader's level of interest and the characters' level of tension on it's way up to the climax. 4)The climax is the moment of highest emotional intensity iin the story. This is the "Oh my goodness. How is this going to turn out?" moment. 5)Falling action are events that take place in the story bringing down the emotional intensity of the story on the way to the resolution. 6)The resolution or denouement (French for final untangling) is where the problems created by the conflict have finally been worked out to a reasonable conclusion.
All three are part of the plot, the plot starts with an initiating incedent then the exposition then the Rising action the the complication then the Climax then the reversal then the falling action then the Catastrphe and at last the Resolution. as for their definitions
Climax: the moment of highest interest and the turning point in a story.
Rising Action: the various episodes that develop, complicate, or intensify the plot.
Falling action: the events following the climax of a story.