A specialized vocabulary or group of words or terms unique to a particular group of people, or professional group of some kind. As writers, there are a number of terms that are peculiar to publishing. This book being a testament to that. It's acceptable to use that jargon with others familiar with publishing jargon, but you wouldn't want to use the same jargon with the public.
In the same way, when writing an article or book that focuses on some topic or group that has their own jargon (but it would be unfamiliar to the average reader), as a writer you need to be careful not to use those terms without explaining them in some way.
However, when you are writing for a specialized audience, and want to be accepted within that group, unless you do use their jargon they will likely see you as an outsider they cannot take seriously.
For more on jargon, go to: http://writingcenter.ua.edu/wp-content/uploads/2012/02/jargonandslang.pdf.