Lightbox2 is a simple JavaScript library used for displaying images and videos in a responsive overlay on a webpage. It enhances user experience by allowing visitors to view media without leaving the current page, making it ideal for galleries and portfolios. The library is easy to implement, requiring minimal setup and customization. It supports various media formats and can be integrated with popular web frameworks. Lightbox2 is widely used by web developers to create visually appealing and user-friendly interfaces for showcasing visual content.