A "Link Preview" is a feature that displays a summary of a webpage when a link is shared. It typically includes a title, a brief description, and an image from the linked page. This helps users quickly understand what the content is about before clicking on the link. Link previews are commonly used on social media platforms like Facebook and Twitter, enhancing user experience by providing context. They can also improve engagement, as visually appealing previews may encourage more clicks and interactions with the shared content.