Photography is one of our primary means of communication, with a rich and complex visual language; we are inundated with photos every day, though they are often unattributed and out of context, and their meaning can be diluted or lost. Written from the ground up by an international team of researchers and experts, this remarkable dictionary explores the 180-year history, technical processes, and evolution of photography, including a long roster of outstanding photographers. Here are 1200 detailed, cross-referenced entries—from Berenice Abbott, Ansel Adams, and amateur photography to Emile Zola, Piet Zwart, and zoom lenses—with more than 300 color and monochrome photos, many of them defining works.