Hypertexts are multilinear, granular, interactive, integrable and multimedia documents describable with graph theory and composed of several information units (nodes) interconnected by links that users can freely and indefinitely cover by following a plurality of possible different paths. Hypertexts are particularly widespread in the digital environment, but they existed (and still exist) also in non-digital forms, such as paper encyclopedias and printed academic journals, both consisting of information subunits densely linked between them. This article reviews the definitions, characteristics, components, typologies, history and applications of hypertexts, with particular attention to their theoretical and practical developments from 1945 ...