An iframe (inline frame) is an HTML element that allows you to embed another document within the current webpage. This can be useful for displaying content from other sources, such as videos, maps, or entire web pages, without leaving the original site. The iframe creates a separate browsing context, meaning the embedded content can function independently. Iframes are commonly used for integrating third-party services, like YouTube videos or Google Maps. They can enhance user experience by providing additional information or functionality without requiring users to navigate away from the main content. However, it's important to use iframes responsibly to ensure security and performance.