2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/211046The purpose of this Introduction, presented at PHOTON2007, is to provide an overview of the basic principles, possible parameters, some technical aspects and the physics program of the photon collider and discuss its status within the ILC project.Talk at Photon2007, Paris, July 9-13, 2007, to be published in Nucl. Phys. B, 17 pp, Latex, 10 .eps figuresAccelerator PhysicsInstrumentation and Detectorstext