Why You Should Use thumbnail for large images?
A thumbnail is a small image representation of a larger image, usually intended to make it easier and faster to look at or manage a group of larger images. Graphic designers and photographers typically use this term.
What is a thumbnail gallery?
A thumbnail gallery is similar to a slideshow in that it displays multiple images on one page, alternating between them in a way that highlights one image at a time. The difference is the visitor gets a preview of the images in a horizontal strip of thumbnails underneath the main image.