Does your Photoshop document have what seems to be a million layers that are all turned off? Instead of deleting them one by one, you can save a lot of time by deleting them all at the same time! This simple feature is often missed by many professionals, but it is really much easier than I ever expected it to be. I'm not sure about later versions, but I know this is possible in both Photoshop CS6 and below…
If you are wondering what role layers play in photoshop, then notice that we may need to edit some part of the image without affecting the other part of the image. In such cases, layers help us in categorizing and dividing the image into different categories. These layers also help us in restoring our previous work in case we edited the image mistakenly. Some users are irritated by the number of layers and these layers create complexity in their work. Some of the users are forced to delete all the layers and start their work again. Thousands of layers create a burden on the users and they are unable to multi-task. With the purpose of facilitating its users, Photoshop stores some of the items in temporary storage or cache just like layers in this example. When dealing in a large number of layers as in complex project, you may get confused so here is the quick tutorial.
First, open any layered Photoshop file and hide a few layers if you don't have any hidden already.
Then, in the Layers Palette, click on the little arrow in the upper right and select “Delete Hidden Layers.”