What i have learnt about Photoshop!

i have learnt in Photoshop that using layer for everything is important because if you made a mistake or don't like it you can delete the layer without ruining your original copy. before editing your image, i have learnt if you duplicate the original image then you always have an original copy to fall back on. however when deleting something on a layer always turn off the eye on the original copy. on Photoshop i learnt how to zoom in and out (hold down alt+scroll, mouse). although through out using Photoshop i learnt to never work n the original copy.