Addendum vs Appendix
You must have encountered a separate section at the end of a book or a journal that is called an addendum or sometimes an appendix. They are similar in the sense that both refer to the information that is always presented at the end of the book. They are both additions that are deemed necessary to be presented to the reader as they are brought to notice after the book has been published or printed. However, the two words are not synonymous as will be clear after reading this article even though some dictionaries make use of one of the two words to describe the other. Let us take a closer look.
What is Addendum?
If a writer has finished writing a book and a new study comes to light that has facts or information that the writer feels must be shared with the readers, he includes it at the end of the book in a separate section called addendum. Addendum is a Latin word that means to add or to give. One can roughly equate an addendum with the use of post script or PS in modern terminology.
However, addendum is not always about bringing to light information from elsewhere as sometimes an author might himself add something to what he has already said in the book. At times, the writer has a desire to explain a point or update something that he has mentioned in the book. There are also instances where authors make corrections to what they have written in the book.
What is Appendix?
An appendix is a separate section at the end of a book that contains information that is supplementary and of such a nature that not every reader might be interested in it to be included in the main body of the book. Such information is mostly technical or statistical in nature. However, appendix can also have useful information for the readers.
Summary:
Addendum vs Appendix
Though there are many similarities in the sections called addendum and appendix that are placed at the end of a book, one major difference pertains to the availability of information while the writer was writing the book. Addendum has information that the author would have included in the body of the book had it been available at the time when he was writing the book. This is the case when a study comes out after the book has been published, and the author desires to share the facts with the readers. On the other hand, appendix mostly contains information that does not fit into the main body of the book but is still relevant for the readers. If anything, the information contained in the appendix is mostly non-obligatory in nature. It is certainly not a must have information.
If information is found that belongs in an appendix, how is it noted in the manuscript? The same question for the addendum.