Photoshop is one of the best photo editing tools ever built. You create your worst photos into something very creative and professional. I have been using photoshop for 2-3 years and still I think there is much more to learn. Like you can't only edit photos but you can also design websites, ui/ux design, make channel art for youtube channel and much more. Layers are the most powerful tool inside Photoshop cause they are the ones which help you in everything that you plan to do in Photoshop.