Art in the modern era has come to be defined by its styles, schools, and movements. The more than three hundred collected here provide an essential introduction to the major developments in Western painting, sculpture, architecture, and design during one of the most dynamic and exciting periods in art history. More than one hundred main entries are presented in broadly chronological order, from Impressionism and Cubism to Sound Art, Internet Art, and Art Photography in the twenty-first century. Two hundred supplementary entries provide fully cross-referenced summaries of additional styles and movements, tracing patterns of influence and development. A timeline shows at a glance how the evolution of art corresponds with historical events, providing a thorough overview of the period. Listings of major international collections and suggestions for further reading are given for all the main entries, and the comprehensive index features over 1,000 artists, architects, designers, impresarios, critics, collectors, and champions of modern art, linking the styles, schools, and movements with the people who made them happen.