James Joyce is primarily remembered for his pioneering use of the epiphany and for his highly subjective, stream-of-consciousness writing style.
Used in his early (1914) collection of short stories called The Dubliners, an epiphany is a sudden moment of revelation on the part of the main character and becomes the climax of the story. Once the main character has had an inward realization that he has been perceiving life through the veil of illusion, the transformation occurs and the story can end. This is different from the traditional Victorian tale in which, typically, an outward manifestation of change must show: for example, in Dickens's A Christmas Carol, the story doesn't end with Scrooge having an inward realization of his miserly living and seeing the light, but with examples of how this change manifests itself in how Scrooge lives thereafter. For example, Scrooge generously helps his employee's impoverished family after his epiphany. In Joyce, however, it is the epiphany that is all important. For this reason, vis-a-vis more traditional short stories, his can seem to end quite abruptly.
Joyce is also famous for stream-of-conscious, in which readers are taken inside the heads of the main characters, following their jumble of sometimes chaotic thoughts as they go through the routines and rituals of everyday life. This can be disorienting for readers used to a more traditional narrative in which the normative (or "normal") voice of a narrator sets the scene, offering us comfort and context. Yet, as with Virginia Woolf, Joyce is struggling to break past the facade of surface reality and describe the reality of life as it is experienced internally in an often fragmented way by an individual.