Both romanticism and realism are plot-driven. Setting is also very important in both. Though both forms of literature share these qualities, they employ them in very different ways.
In romantic literature, the "greater purpose" of the plot supersedes character development. Throughout the story, characters maintain many, if not all, of the qualities assigned to them at the beginning of the story because the intent of the author is for them to drive the plot in their existing form. If the characters change, then the overall meaning of the story would also change. Realism is also plot-driven. Characters, however, do not remain static in realism. As the plots evolve, so do the characters, and much of what takes place within the plot is intended to spurn that evolution.
Setting is also essential to both types of literature. In romantic literature, the setting is often isolated or unique. The very quality that defines the setting is integral to the story. In another setting, a romantic story often could not happen. Likewise, in realism, setting is equally important in that it plays a key role in creating the atmosphere and, subsequently, the conflict of the plot. In this way, settings in realism sometimes take on the qualities of a character and, in doing so, shape many of the characters' responses.