Have you ever worked on multiple layers, such as stacked thumbnails, and you wanted to turn each layer into its own document? It’s easy. Choose File>Export>Layers to Files and you can choose where you want to save the files and the file format. Each layer will be exported as a new image file. The names of the new documents will include any prefix you add in the dialog, a sequential number, and then the name of the layer. So, you might want to name your layers first (I caught you, didn’t I?); otherwise, the documents will have “Layer 1,” “Layer 2,” “Layer 2 copy,” etc. at the end of the filename, which doesn’t tell you much about that document.