A thumbnail image is a small, low-resolution version of a larger image that is used as a preview or placeholder. Thumbnail images are commonly used in web design, digital photography, video editing, and other media applications to provide users with a visual representation of content before they click or view the full-size version.

Thumbnail images are typically small in size and dimensions, often ranging from a few dozen to a few hundred pixels in width and height. They are often compressed or optimized to reduce file size while maintaining acceptable image quality, making them quick to load and easy to display on websites, search results, file browsers, and other digital interfaces.