The word compendium is a word that is used to refer to a set of elements that have something in common and that are grouped precisely due to those possible similarities. Usually, the term is used to designate written or digital works that comprise a significant number of knowledge related to a particular subject or area, such as an encyclopedia does, although perhaps it can include diverse topics while the compendium specializes in a particular subject. In many cases, the encyclopedia is considered as a compendium or a union of all the knowledge and data that Humanity has generated over time.
The term compendium comes from the Latin term compendium which means summary, condensation. Thus, we can understand that a compendium is not an extensive work on something but rather tends to represent a sum of the most important and significant elements of a particular subject, for example when speaking of the compendium of ocular medicine. It will then appear the most relevant knowledge and data that can be of use to someone about the aforementioned subject.
Other characteristics of the compendium have to do with the fact that despite being a summarized version of all the knowledge that may exist about something, it is also a very detailed and deep description of what it is about, so its usefulness is always very big. It must be borne in mind that in general the compendia mean a very specific set of knowledge, and that is why the summary is facilitated in this way: we could not easily find a compendium, for example, of all medicine, if not that we can find instead a varied number of compendia that are interested in different parts of medicine, for example a compendium on pediatric medicine, another on cardiological medicine, etc.
