Nonfiction works, if scholarly studies or published hardcovers, oftentimes build in many appendices. Provided there's good one, it's called an Addition. Besides than one, and you accept several appendices. Don't be confused by the term referring to a part of your anatomy--book appendices are significantly more useful.
Function
Appendices store information pertinent to a topic, but not required to understand the topic. They may include examples of code if you're reading a book about C++ or SQL. The raw data may prove distracting if included in the main body, so you place this information in an appendix.
Significance
An appendix provides supporting information for statements you make in your core document.You generally create appendices as you write. You may find, for example, that if you're publishing the result of a study, you want to provide the raw data. In this case, the results are critical, so they form the main body of the document. Or they may include a timeline of an event to provide background to a biography. You may also use the appendices to include charts and graphics, and refer readers to the appendix with that information rather than including it in the core document.
Time Frame
If you're writing a legal opinion, you may cite a legal ruling to support your argument. In this case, you may place the entire legal ruling in an appendix and refer the reader to the exact phrasing that supports your case.
Considerations
Some scholars think of an index and bibliography as an appendix. Though they are appended to the end of a document, they have become so common that many writers prefer to think of these items as separate items of value in and of themselves. Appendices, on the other hand, are regarded as support documents solely.
Potential
Some appendices are produced to correct errors in an original version of a document. If this is the case, you must refer to the appendix of corrections to be sure you have the current and correct information. Additionally, if a work is initially published and becomes controversial, the author may write an appendix for later editions that outlines arguments in support of the original work or provides further detail.
