What's Thumbnails? What is the function Thumbnails?
Thumbnails is a term for the small picture display mode which represents a large picture for ease in selecting the picture by looking at the name while viewing the image contents.
Like computers and smartphones, before we see a picture will certainly appear small picture that represents the image. And the picture exactly as the original image, only smaller size alone.
Thumbnails function is as an initial appearance before a picture is selected, so that we can easily select which image you want to display, moved, deleted, etc., to speed up the process of displaying a preview image in the folder.