A contact sheet is a piece of photographic paper on to which several or all of the negatives on a film have been contact-printed as evidence of a photo shoot. They are essential as they help organise photos and make it easier to decide which ones to use.
This is the start of a contact sheet of my dog which should be 36 images. Some of the photos have been edited and cropped. Narrowing it down, the bottom left and right photos as well as the top middle are my favourites and should be circled.