One of the bestand worstthings about Photoshop is the sheer number of things that you can do with it. Think about it: Photoshop is used in fields such as medicine, forensics, science, fashion, and so on, and it's as important a tool to those users as it is to us as photographers and creatives. Adobe continually adds features to Photoshop to solve more types of problemsbut those additions also increase the level of complexity in the software.
When teaching about Photoshop, one of the most common statements I hear is, "I just want to learn how to do x. I don't really need all the other stuff that Photoshop can do." These users could be served by a stripped-down version, removing any functionality that they don't need, and leaving just the "meat" of their particular application. Of course, that approach wouldn't take into account the user's growing skill level. As a user got better at working with the application, this streamlined version of Photoshop wouldn't be powerful enough.
A better solution would be for Photoshop to evolve with users, letting them specify which portions of the application they could see at a given point in time. That's one of the most important reasons to use panels (sometimes called flash panels): By creating specialized panels for Photoshop, you can customize the user experience so that it "evolves" as the user's skill with the software improves. This article shows you how to use Adobe Configurator to create and work with panels.