Photoshop doesn’t just support multiple color spaces, it supports infinite variations on the device-dependent ones. You can open an RGB photo, process it in Lab, and output it to CMYK, with certainty that the conversions will work.
America likes its lists, and here’s another one. Imaging expert and award-winning author Deke McClelland presents his list of the top 40 features in Photoshop—beginning with #40 and working his way up to #1—one weekly video at a time. Some are tools, others are commands, still others are conceptual. All are invaluable. Learn these 40 features and you’ll know Photoshop.