Task
In Photoshop, you will need to sort out your files which will organise your work and it will make your lives easier.
Export
In this files, once you have finished your work, you upload it as a PNG or a JPEG to show a printed copy of the file.
Images
In this files, these images are used in your work and it can be used as references.
PSD
In this files, this file can be used to edit and comment on your work.
Screenshot
In this file, it will help you record on what you have done in your work.