Dictionary of Critical Terms
GENRE -- critics use this term to identify specific texts with kinds or types of literature. It can refer to a category as large as "prose fictions" (i.e. all novels belong to the genre of prose fiction), or more specific categories within larger ones, so a novel can be said to belong to one of many different novelistic genres. It's not an exact term, and it can be argued that as a label it obscures as much as it helps explain or describe, but generic distinctions are often in writers' minds as they write and, especially, in readers' minds as they read, so that they expect certain kinds of things to happen in the various genres.
Charlotte Temple, for example, is usually associated with the genre of sentimental fiction, or even more specifically, with the novel of seduction. Literary historians trace the history of these types back to the novels of Samuel Richardson, especially Pamela (1740) and Clarissa (1747).
Wieland is usually referred to as a gothic novel, a genre that is traced back to Walpole's Castle of Otranto (1765).
NARRATIVE TECHNIQUE -- the way a writer chooses to tell a story.
Charlotte Temple, for example, is written in an omniscient third-person narrative style, in which the story is told by someone who is not a character in it, and who knows and can share with the reader the actions and thoughts of the various characters; in some texts the third-person omniscient narrator addresses the reader directly, as Rowson does at a number of points in Charlotte Temple.
Wieland is written from the first-person narrative style, which means that a story is being told by someone who is also a character in it. A first-person narrator often is, but doesn't have to be, the central character in the story. An unreliable first-person narrative (sometimes called an ironic first-person narrative) is one in which readers are expected to understand the story in ways the narrator doesn't or can't.
Because Wieland is written in the form of a letter from Clara to some acquaintances, it could also be called an epistolary novel (as Brown in fact does in his "Advertisement"). Epistolary novels were often very popular in the 18th century (following Richardson's success with the form); novelists still sometimes use it, as Alice Walker does in The Color Purple. An epistolary novel conventionally tells its story through a series of letters back and forth between various correspondents, some or all of whom are also characters in the story being told. (Because Wieland is essentially one long letter, is isn't a typical example of this narrative technique.)