The best and most important photos redefine the way we see our world. They show us history-changing moments, such as the D-Day invasion or the assassination of a president. They capture cultural touchstones, like the March on Washington or the rise of Beatlemania. They help us understand our universe, showing us what Earth looks like from the moon and what’s happening inside our bodies. In this photo age, with people sharing millions of images each day that fly past in a blur, LIFE’s editors have selected the 100 most important photos ever, with the greatest lasting value, and tell the surprising stories behind them, from the Iwo Jima flag raising to Brandi Chastain’s soccer celebration. The book includes a section about photography itself, showcasing images that changed the way we use cameras, from selfies to mug shots and wedding pictures to photo finishes. Readers will walk away with a fresh appreciation of the power of the picture.