We've all seen the masks signifying tragedy and comedy. These are two types of plots. They're not as we always see the, Tragedy plots are more physical and comedy are those of the mind. These are two basic plots and to look at them gives one an idea of what kind of plot they're setting into words.
Tragedy of physical plots are those that pit might and power against each other. Comedy plots often show two or more people matching with and coming up with a story. But these two forms of plot have many variations. So when you're writing your story, you need to isolate just what form your story will take.