I think you will find all the information you search for in this book (there are plenty out there on the subject).
Anyway in brief terms inflammation is a reaction of the body to a deleterious event (eg too hot, too cold, dangerous chemicals, radiation, toxins etc) that could happen on a small (cellular level), or large scale (organ level) and in a little (a paper cut), or long time (chronic diseases) and provokes cellular damage.
It involves a cellular and humoral response but it's really a big issue, difficult to solve in just a post.
The invisible inflammation you mentioned falls in this field, but it depends on the specific subject since inflammation is involved in practically all the human diseases.
Hope it helps
i changed the second link since it was not freely available to everyone.