An encyclopedic scientific and informational conceptual study dedicated to the largest transition period in the history of culture - the artistic and aesthetic culture of the 20th century - from classical Culture to a fundamentally different aesthetic consciousness and art processes of the technogenic-computer civilization of the 21st century. An open hypertext of articles correlating with each other and other intertextual phenomena, revealing the specifics, main trends, directions, system of concepts and terms established to designate them, as well as the main personalities of the artistic and aesthetic culture of the 20th century in the context of the main paradigms of the European classical tradition, as its logical conclusion. At the same time, the main attention is paid to innovative, non-classical, post-classical phenomena and personalities that characterize more than a century of movement in the cultural space: avant-garde - modernism - postmodernism, in the spheres of aesthetic consciousness and visual arts, mainly, but also in literature and music from symbolism and impressionism to the art projects of the late 20th century. Lexicon articles take into account the latest achievements in the field of humanitarian knowledge, are written in a language accessible to the widest readership, and are equipped with a rich bibliography. The book contains an index of names and a Summary.