A lightbox, also known as a modal or overlay, is a web design technique that displays content in a floating, centered window on top of the current web page. Lightboxes are commonly used to:

• Display larger versions of images, videos, or other media content
• Present forms, surveys, or other interactive elements in a focused, distraction-free manner
• Display important announcements, notices, or calls-to-action
• Showcase product information, previews, or demonstrations

Lightboxes are designed to draw the user's attention and create an immersive, focused experience. They typically include features like the ability to close the lightbox, navigate between content, and interact with the displayed elements without leaving the current page.