ImageReady includes many of the basic color correction, painting, and selection tools that you've already learned in Photoshop, plus a powerful set of web tools for optimizing and previewing images and creating GIF animations and rollovers. But before you can work on a picture in ImageReady, you have to get it there. There are a couple of ways to do this. If you've been working in Photoshop, click on the small icons at the bottom of the toolbox. Initially, this action opens ImageReady with the current Photoshop image loaded; when both ImageReady and Photoshop are launched, click this button to toggle back and forth between the two applications. You can use the keyboard command Shift--M (on the Mac) or Shift+Ctrl+M (in Windows), to toggle between the two programs. Of course, you can always open the picture to be worked on from within the application.
What ImageReady can't do is print. Because it's intended for web creation, it works only in RGB mode, and only in 8-bit color (what a monitor displays). Now that we're seeing web pages on TV sets and even on cell phones, it's more important that images on the page fit with the display standards.