This document discusses the history and techniques of photo manipulation from the 19th century to present day. It covers traditional darkroom techniques like retouching, double exposures, and hand coloring. With the transition to digital, new tools like Photoshop emerged allowing for techniques like dodging and burning, spot healing, compositing, and adding visual effects and filters. The document also discusses examples of manipulation in advertising and the potential legal and ethical issues it can raise by creating unrealistic expectations.