This is an attempt at outlining the theoretical and methodological framework of a genological approach to the compendium and the compilation. The two genres which have become enormously popular in the last decades chiefly because of the rapid spread of modern communication technology surely require a fresh reassessment from the point of view of literary theory. The word 'compendium', for instance, can now refer both to a comprehensive academic survey of a given discipline or field of study and a simplified, time-saving study guide. The latter is popular with the users of the internet where it has extended beyond the traditional areas of academic and general knowledge to cover any type of record of public activity. The author of this article reconstructs the original meaning of the word 'compendium' and its transformations over time. He notes the analogies and the way it overlapped with the meaning of 'compilation'. Judging by the history of both terms, they owe their popularity to the rise in popular demand for various kinds of knowledge, especially in those fields that are broadening and need up-dating. The mechanisms of the present surge are basically similar those that operated in classical antiquity, the Middle Ages, or the early modern phase.